Drivers and shop staff between a rock and a hard place, usual " experts" on here moaning.
Do they actually imagine the vast majority of drivers and shop workers want to put up with the constant stream of abuse and harrassment they get? Here is a clue, no they don't. If they don't follow the rules there will be some sad **** videoing it and making a compliant.
The government tell them to do one thing, the company tells them to do this, the public ( or at least a significant number of them) treat them like dirt.
If I see someone I don't like my " bus full" sign goes on. Serves them right.
I think the majority of passengers realise the driver is just doing what they are told by "higher ups", but they are the public face of the company at that moment in time. You've posted repeatedly about lack of understanding from your (former) management; perhaps those passengers who are "having a go" at the driver are merely passing on the frustration they will experience from their own managers? Surely you can understand the perspective of a passenger who, if they can't get on the particular bus, will be late for work, late for childcare, late home after a day rushing around freshly re-opened shops, momentarily doesn't manage to keep their frustration in check when told they can't board? Have you never had a sharp word for shop staff if they've kept you waiting after a full days driving?
Attitude is a two-way thing, and we are all human: there are some passengers whose attitude leaves a lot to be desired, but some drivers likewise. Take an example from Saturday. In this area, although a normal timetable was running Monday to Friday, it was still heavily reduced on Saturdays (including to one of the country's biggest shopping centres).
I'm at risk of an off-topic warning here as my personal experience doesn't directly relate to "bus full", (there were about 10 of us for an advisory capacity of 17), but the driver arrives, unloads, ambles off without a word (presumably for a 'bio-break'), ambles back, closes the doors behind him, then sits for about five minutes with his hands clasped on the steering wheel, then eventually taps into his ticket machine, loads passengers, and we leave about 7 minutes late on a service running every half hour (every 12 in normal times). He didn't acknowledge a single passenger on boarding or alighting. Would it really have been too much to ask for his customer service to have said "I'll be back in a sec" and "sorry, the ticket machine took ages to load"? Or is that somehow acceptable for him, but the passengers (a mix of leisure and workers) have to be understanding, sweetness and light? If I'd have been the 18th passenger in the queue and told I couldn't board after that behaviour I think I've have struggled to smile sweetly and step off the platform without a sharp word or five.
The contrast with a local inspector (sorry, duty manager) in a different town (same company) a week before, who was swapping buses all the place to adjust for capacity and make the best out of a bad situation was stark. Who got most thanks from intending passengers?