I've been using Jetbrains products for free in college and I can say that it is the best advertisement. I bought it the day after my student license expired.
Ehh even when I was in school I used foss like blender and gimp. I've never had an actual copy of 3dsmax, Maya or photosoup. Been plenty productive with that my entire life.
Yeah, that's really unfortunate. I think the market would be way more dynamic innovative, and secure if such large packages would be foss. Larger companies can have their own full or part time specialists, and smaller ones can put out bounties etc
Some software uses license servers where each client is supposed to request a seat temporarily. If more people use it at once than seats were licenses they detect that with phone home features. We had that with Matlab I believe, if you tried using it in the most popular time you might not be able to.