It's an interim measure though and probably the least disruptive.
There are very few people who travel from Wellingborough to Bedford. On the times I've used EMT services into London during the peak, you can count the number of people alighting at Bedford on the fingers of both hands - so that includes people travelling from Wellingborough and points north. Luton Airport is far more popular as a stop.
Things will change when the Corby electrification is complete and EMT introduce a half-hourly service from St P to Corby, which will call at Bedford, but in the meantime it's about making a compromise which impacts the fewest number of people and I'm afraid passengers travelling to Bedford from the north in rush hour are that group.
This argumentation appears logical, probably mathematically correct, or at least justifiable - but I would argue is deceptive. The the best way I can think to describe it for now is "mechanistic".
Let's be clear: there are two problems here. One is getting the huge number of Bedford commuters from London back to their 'home' station in reasonable comfort and asap. The other is the practical difficulty (ie pathing) and economic cost in stopping - or not - EMT trains in the peaks at Bedford.
The planners have taken your approach. Let's say they can get an extra Thameslink train or two in to help solve problem 1 while eliminating EMT stops. Maybe 4,000 MML commuters between Bedford and key stops to London get more seats and more trains, even if some of them are a bit slower. That sounds like a deal. Can argue about the details, but there are advantages.
Meanwhile EMT fasts no longer stop at Bedford, and pax north thereof enjoy 2-3 minute faster journey times in the peaks. That also sounds good for a good few folks on board. A lot of people-minutes to add up over a year's travel.
And at what cost? Maybe 'just' 150-300 customers in each peak - each three-hour peak according to the press release - are to be "inconvenienced" a bit by having to catch buses. (The numbers are my guess, from what I read here - I'd assume fewertowards the lower end in the up peak, and more who'd like to join at Bedford in the evening peak. We don't know the times yet, but I'd assume a gap in departures north from Bedford from something like 16.30 to 19.30.)
That is the sort of logic you and the planners are using here - and put that way, the whole deal sounds reasonable, or at least, not too bad - certainly not from the numbers point of view.
But Hadders damns this deal - the bus deal - as "unacceptable". And I can see why. The problem is that while a lot of people (commuters from Bedford, and EMT passengers frodm the north) arguably get a marginally better deal - the services between Bedford and Wellingborough are - in terms of modern travel conditions - destroyed in the peaks. These passengers are to make their ways (with luggage?) out of the stations to buses (will there be staff to help direct them?) - endure a vastly slow road journey - and - if they are to continue their journeys further - back into the station. This is not a one-off pain because of some emergency, it's not for a week, nor even a month - but for something approaching 2 years.
I'm sure a few regulars will just grin and bear it, and some who can will adjust their journey times to avoid the bus - but for many this chop-change-slow bus will simply be unacceptable. This will surely be true for a good chunk of those who already have to change at least once - eg coming from Flitwick, Harlington or the Bletchley line and wanting to head north to Leicester and beyond. (It would be interesting to know what percentage of passengers heading north from Bedford actually originate from elsewhere - my guess is about 35%?)
Yes, the numbers that 'suffer' from all this may be low compared to the Bedford-London commuters and the compromise looks good on paper, but passengers between the north and the Bedford area will see their services devastated in the peaks - and my guess is most will find other ways of making the journey. Because, as Hadders says - it is not acceptable.
And, as he also underlines - once these things go for a "temporary" period - all too often the operators find it convenient to keep it that way.