I suspect lots of people will have but would have rationalised it as they are just a cog in the machine so can't do anything about it and/or it culturally it was made clear such dissent was very unwelcome.
There's a small number of suppliers who get these kinds of contracts. They have extensive relationships with government. The politics of the contracts outweigh pretty much everything else. It becomes like a mutual death grip, the buyers know it's all going to ratshit but to admit this is to shine a light on their own incompetence and inability to control their vendors and the very nature of how these contracts are awarded. The vendors themselves are locked into a culture where they habitually take on more than they can chew because (a) they're allowed to so and you end up with de-facto business models that are completely dysfunctional but viewed as 'normal' (b) there's actually a fair degree of delusion in what they they think can deliver (c) there are rarely any meaningful consequences that would force them to reconsider their business model.
So you have buyer and vendor complicit in a high stakes game of pretending everything is normal when it's anything but. Sometimes they get away with it by muddling through and delivering something that puts sufficient ticks in boxes that they face no further scrutiny; sometimes external events provide a face saving way to allow the systems to be written off before a reckoning comes; sometimes things blow up in their faces and they get found out which is what appears to have happened here.
Normally the significant but indirect losses we experience as tax payers through these disasters can be swept under the carpet. However this time we can see the very personal direct consequences it's had on large numbers of people (and not a marginalised group of people who will not garner sympath) and so people are quite rightly outraged.
For anything good to come from the awful experiences of the victims in this case then beyond the appropriate compensation there also needs to be a real root and branch review of how the public sector in particular engages with these mega suppliers.