I think your product managers are doing it all wrong. They should be showing up with "this is the problem we've identified" and asking how the makers can solve it. Product management looses out big when they show up with "this is the solution we demand".
Yes, that would be great. Unfortunately there is no incentive at all for product managers to have that sort of positive and forward thinking attitude or working relationship with engineering. Instead, 99.9% of product managers have every political incentive to take the approach of 'I have the word manager in my job title therefore I am everyone's boss and they must work to meet my demands' Inexperienced engineers won't challenge this and every other person on the team loves the idea that engineers are their underlings, so that becomes the culture and work environment.
