For one, I doubt very much anyone told the developers of the new task bar that it shouldn't be movable to other screen edges. I'm confident that was a design decision by software engineers who deemed it too difficult or time consuming with no regard to how it would impact people who have used that feature since Windows 95.

But even if they had, I don't anyone gets a pass on building a crap product just because they happened to get paid to do so. If your situation is such that you can't risk your job by refusing to do it, you can at least own it and feel an appropriate amount of shame.