If I may issue a clarification, at least part of the problem is that people gladly invested in DLC and paid Paradox money on the hope that they NEVER WOULD BE used as cash cows, that they always had an option to enjoy the base game and not feel like things that should be core features held for ransom unless you paid $15.
And they're starting to wonder if all the money they already invested was based on a false pretense.
This is the first time that a truly core mechanic has been behind the DLC paywall. What I mean by this is that development is something ou are supposed to do, regardless of what nation you play. The map is now balanced in part around the development mechanic, especially for colonizers. There's no workaround, and thanks to decisions already made, they've painted themselves into a corner about giving core players the development mechanic or anything like it
This is very different from the way, say, Colonial Nations were handled, or new religious mechanics, or anything else there has been DLC's. There was a way to avoid these features while still feeling like you were playing the game more or less as intended, and a basic functionality that imitated the DLC content was put into the base game for core users. Not so with development. Those buttons are on anyone's screen, right on the heels of an update that removed the core building system we paid for in the base game, that did a lot of the same things now handled by the DLC-lockd Development button. That's what's different.
With the development mechanic combined with the map rebalance that really isn't true anymore and there isn't even the feature-depleted analogue that made waiting to buy CoP palatable..