I don't think the "ecosystem" argument is as unreasonable as you think. If people are used to games being a certain price, a sharp increase will raise some eyebrows and feel out of place, whether warranted for that specific game or not.

I'm not sure "entitlement" is the right word, but I definitely think the reaction is based on simply not wanting to pay that price for the game. But if SE can make enough money on the game by charging that price, then there's obviously nothing wrong with their price model. If there was, the company would be forced to charge less. The people that whine the loudest are probably going to buy the game anyway.