The main complaint is: I need my Adobe. I need my Ableton. I need my Office.
Some people actually need the official Office products, but I think for most users it's not necessary, though they get really uptight if you suggest it's not.
Adobe is honestly one of the biggest problems I think, and the most likely to continue to cause an issue with adoption.
Ableton can sorta work, but it's not perfect, but I can see them starting to pour resources into it to get it working better or even a proper port, but I could be wrong.