First of all, you can get your point across without resorting to petty insults, and secondly, Im smarter than you could ever hope to be.
Now, I understand this is not good for the tiny fraction of modders who are looking to commercialize their games. I think thats pretty obvious. Nobody is arguing that it is good for gamers.
You asked, "What if 5-10 years from now every company treats their communities like this?"
So be it. If its such a big problem, than you need to make a statement by not buying the game. If the games are still wildy successful with these restrictions, than nobody actually cares anyway.
Youre talking about a very tiny fraction of gamers. Most modders are not looking to commercialize their mini games.
This is not going to kill modding communities. Most modders just hope to make a game that others will enjoy, and if people play it, that is good enough.
Maybe its not ethical in your view, but nobody is forcing you to buy the product. Its their product therefore its their choice.
You have to look at things from both perspectives, not just the gamers perspective. Businesses always do what is in their own best interest, this should not be that surprising. From a business perspective it makes sense.
If you don't want blizzard taking your mods and building games off it, then don't make it using their platform. Therein lies the problem for modders. Without the game, the modders would never be able to make those games in the first place.
Do I think blizzard should be able to take your idea and sell it as their own game? I think a 50/50 or 70/30 split would be "fair". However, businesses don't go by what is fair, because they operate entirely to procure profit. That is the nature of business. Very few things are fair in this world.