Because your 0$ per month after dropping them doesn't hurt their bottom line.
Corporations generally weigh the risks and the benefit often wins out and they make more money because there are enough people that either reluctantly cave into the fee increase, forgot about their subscription or just don't care that it's going up.
It's fairly seldom (but seems to be increasing over the years) to see so much backlash that a company walks back on what they were planning to do.
They probably will if they get a takedown request.
I'm guessing you are uploading US related material by your comment.
If you are concerned about it, like maybe you have an account that you don't want to lose, then make another account and upload it.