Well it would seem remiss for me not to respond to such a fulsome set of comments
Most of these issues would be solved if bus travel had more investment, or if the way of operating buses in the UK was changed. Every other country with an organised bus system in most cases use buses with more than one door and have no issues with operating them.
Hmmm.... well that's a rather fundamental issue. The old adage of...well, I wouldn't start from here. Yet, here we are...this is the position that we find ourselves in.
And how are we to pay for the rather extensive wishlist of financial commitments? Think of it from a political point of view... Taxing people more is always a surefire vote winner and whilst it might work for the NHS or Defence, there are few votes for politicians from taxing people more and not for public transport. And if not taxes... what would you instead cut? Removal of the triple lock, or perhaps reducing disability benefits? What of the other major policy issues that are also demanding investment? Like Defence, or building more council houses, or investment in SEND and social care?
More investment - easy to say, not easy to deliver
1/2. Not really an issue, as buses themselves cost a lot of money to purchase and operate, if the large operators weren't so obsessed with cost cutting this wouldn't be an issue at all
All operators manage costs. In fact, we all manage costs in our every day lives. I'm sure you do in your daily life?
3. This could be solved if longer 12m buses or 100% low floor buses like the Citaro and Kite Electroliner were the standard, unlike the current standard which seems to be 10m-11.5m. I understand the UK has tighter roads than most other countries, but in countries like Italy and Swizerland who in many cases have much narrower roads than the UK 12m is still the standard. And in recent years a lot of shorter single deck E200s, Streetlites, Versas ect. have been replaced by longer Yutong E12s and MCV Evoras.
Erm... Yutong E12s seat about 39 passengers... less than long Streetlite or an Eclipse. Reducing them to 35 seater dual doors for more standees...
4. This wouldn't be an issue if the UK, like most other countries in Europe hired ticket inspectors, (alternatively perhaps somebody could develop a CCTV system to detect fare evaders and notify the driver/operator). Or we could lower fares so theres less incentive for people to fare evade (UK ticket prices are significantly more expensive compared to our neighbours like who offer much higher quality service compared to even our best cities for public transport).
And maybe the UK bus system could realise running a bus network and maximising profit at the same time is impossible without severely limiting mobility for those without a car.
So more expenditure on ticket inspectors or you'd like lower fares? Getting to be quite the wishlist here.
5. Adding a second door to a bus only reduces capacity by 2-4 seats which isn't very much when a double decker bus can have up to 90 seats. Single door conversions exist, and they do cost money, but ex-London buses seem to be the most popular for smaller operators who tend to operate school work. In other European countries provincial operators in the majority of cases run 2 door buses, so I don't see why it can't be the same here.
It typically reduces it by a minimum of four. For a double decker to have 90 seats, it needs to be long wheelbase (even triaxle) and that's not always conducive to operation. Ex London deckers are used for provincial ops like schools but that's because they're cheap having been returned often off lease and hammered into the ground after 14 years on the capital's streets. It's rather different in provincial operations.
6. This only becomes an issue at a few stops, but that's just where I live. At the few stops where it is an issue, it wouldn't cost a lot to solve this, by extending the unloading/loading area, at bus stations and the few stops where it's impossible people can exit through the front door and at bus stops it isn't problem as buses wait for long periods of time.
Another substantial cost implication just waved away. There are plenty of stops that would have issues. One from near me that I passed earlier today...

The shelter would need to be turned 180 degrees and the Kassel kerb moved because were you to stop the bus with a centre exit level with the kerb, you are blocking an access. On this particular road, some additional bus priority would be immeasurably better in making bus services quicker and more reliable. So there would be thousands of examples around the UK to tackle and, in many places outside the major cities, it simply isn't worth the money.
Many DIRO bus stations would have issues so you'd have to be dropping off elsewhere.
7. This is more of an issue with the UK bus system, as buses here are seen as the main transportation into the city centre in large cities, rather than secondary to trams like in most large European cities, where a bus would normally connect outer suburbs, or take passengers from suburbs to trams stops or railway stations, where they can make their connections into the city centre while the bus continues to the centre but on a much slower indirect route.
Yes, but we're in the UK. Saying we should be somewhere else is rather like my comment in #1... We wouldn't start from here, but here is where we are!
Some could argue one door is best suited for the bus system in the UK, but the UK bus system itself is heavily flawed and UK bus networks are often look like they were designed specifically for people who don't have access to a car, rather than something that can compete with cars.
Firstly, it is very unlikely that you can readily compete with cars. They provide virtually ultimate freedom if you have one. However, if you want to level the playing field...
You have to make it more difficult for people to drive into cities AND to park. That is potentially politically toxic. The cost of private car ownership has also become much cheaper so whilst fuel prices have outstripped inflation (and that affects bus operators just as much), the other costs such as insurance or purchase costs are lower. Also, because cars have become more efficient, that fuel cost is actually lower overall, whilst buses are held at a higher bar and so their fuel efficiency is often worse as they have to meet more stringent emissions targets.
You could, of course, have congestion and clean air charges... remind me who kyboshed the Manchester CAZ? Never underestimate the considerations of politicians.
I suspect that most of us here would think that the policy of remaining in one's seat until the bus stops is rather silly. From a company point of view, however, all it takes is one passenger to have a fall and injure themselves as they're getting up from their seat to generate a "blame-claim".
And that has been the catalyst and the rise of no win, no fee shysters. It was prevalent in the early 2000s so companies started making that request so then if you did stand up and then fell, no case to answer (hopefully).