In short, although owners own the assets of the club, they don't really own the fanbase / legacy of the club.
We have a property (call it "fan equity" or "club legacy") that someone (fans) has invested time and effort in improving. That property has now acquired commercial value so now the govt (club owners) want to use the eminent domain argument to take that and use it as they wish.
The eminent domain plays as follows: SL12 owners are looking to de-risk their business, ie avoid financial volatility. In effect, SL12 is for the "greater good" of the top clubs. (investors would lose far less money, which means top clubs would have guaranteed financial futures, and thus, never disappear)
This does not appeal to the fans because they are invested in the ups and downs of their clubs. They are OK with downside because they also have the upside. This is similar to a property holdout. They dealt with the bad times in the neighborhood...so its natural they say now when the going gets good.