The biggest problem with the change is there is FAR to much animation happening in the tool bar now. All that motion just creates visual noise, making the entire thing more difficult to interpret.

This is basic human factors and basic communication theory. You need to keep the "noise" down for people to get the signal.

The entire attitude in the developer post is condescending and insulting. It is common for anyone whose creative output is challenged to become defensive. Making slight tweaks isn't going to fix this. SE need to admit they made a mistake and fix it by restoring the old icons while either working on a new solution that is not so visually cluttered or just moving on to more important things.

Unfortunately, with the exception of the massive, almost company killing mistake made in 1.0, SE never admit to mistakes and continue to push forward, knowing that their customers are just ignorant and will eventually see the brilliance of their design. "It's not a problem in design, it's a problem in communication. Let's just tell them they are stupid and all will be well!"