That's a good point, this does happen. But I think those cases are fairly rare and give you an excellent opportunity to raise this issue with management as soon as you become aware of it and then to move on if they do not wish to have the situation improved. Otherwise you'll just end up harming your reputation by trying to solve the unsolvable and ending up getting the blame for it.
Usually it will not take 10', 100's or even 1000's of hours to know which way things will swing in the long run.
Not rare. We're not allowed to use certain tools and services for odd made up reasons. These decisions are made by people that are incredibly distant from the actual production.
An example is that we're not allowed to use crash-analytics tools but we are however allowed to insert Google Analytics.
Yup, I've also seen this happen pretty often. The problem with working as a consultant is that it's difficult (or it's assumed you shouldn't) be in contact with various 'decision makers' of the client. You can of course suggest to the client many times that something is broken, but it rarely gets fixed. Instead the fix is to create various workarounds time after time.
Usually it will not take 10', 100's or even 1000's of hours to know which way things will swing in the long run.