There’s one issuse: Not everybody has the capacity to interpret the lengthy legal document. While being reasonable, when was your last time sit down and have a good read of the EULA and other related documents? These documents are designed to be difficult to read, and often intertwined with legal concepts that most don’t understand. That’s why lawyers exist.
Then the next question is: should a product a consumer bought (not lease) be completely dysfunctional after a undefined period of time? Is the petition asking for the servers operate indefinitely regardless of revenue? No. The petition is asking to not make the game completely unusable after a server shut down because of an always online DRM or something alike. The online part can go away and we can all enjoy the offline campaign like 10 years down the road. I don’t think this is a request unreasonable to make.
Your interpretation of such action’s legality is valid, but legal is just the minimum bar of ethical, and seems like there is a need to raise the bar.