I get the reasoning in theory, but... it doesn't work for everyone.
Speaking for myself, I don't appreciate the anxiety. I only played XCom EU but the timed missions were the ones I hated the most. I just didn't want to play a game that was just that every time. It doesn't make me thrilled, it makes me stressed. I do actually want to inch my way through every mission, so I can stay prepared for danger, since the game will pop out a bunch of enemies with free actions at any moment. I felt like the commander of an elite team whenever I managed to badly damage any enemy even before they got the chance to attack.
When they "fixed" me "optimizing the fun out of the game", they just took me out of the game entirely. What they see as fun or not fun is not universal.
Some might say that if this is how I think maybe that's not the game for me. But if having both possibilities is an alternative, why shouldn't I be able to play the way I actually like it?