Orange Juice Can Syndrome, at least that's what I call it.
There's a part of your brain that tells you how long things should take. It starts blaring klaxons if something is going to slow. It also resets itself when exposed to a faster way to do the same task.
A good metaphor is an orange juice can. Back in the day, orange juice came in cans much like soup. You'd get out a can opener, open the top in the morning, and that was your orange juice for the day.
Someone got the wise idea of putting it in a paper carton. Now, instead you open up one end, press the sides and squeeze in to make a nice little spout. Then, someone put a hole on the side with a screw-on lid. To break the seal, you just unscrew, peel the foil, and pour. But sometimes that foil can be tricky, so they replaced it with a plastic ring. Hook your finger in, pull it off, and that's it.
Now that we've been using the plastic rings for a while, it's inconceivable to go back to the cans. Even the foil is annoying. Same thing with 3.5. It was a good idea, a great innovation, but now that our brain has been exposed to an improvement, some part of it rejects the old way.