There are likely more people who want to get in but can't, either because they couldn't nail an ADR or because the lounge is full, than people who can get in. So that argument doesn't win any sympathy. There will always be people who can't get in; the question is what is a fair usage (not necessarily expenditure) to justify admission.
But it does focus the issue on why some of us have an innate feeling that certain approaches are unfair, either to Disney, servers, or other guests. And fairness is innate; there are experiments showing some primates (either chimpanzees or monkeys, I forget which) have a sense of fairness. That explains why we can feel strongly about it without being able to verbalize our justification or base it on solid logic. It also explains why we may disagree.
The amount spent is part of the picture, certainly in terms of fairness to Disney and the servers. Even so, be careful. It's not clearly a fair argument to compare an average amount on drinks and dessert against a rock bottom amount on entrees with no beverage or other costs; shouldn't it be an average amount on just drinks or dessert versus an average amount on entrees and the other things people who order entrees also get?
Even if that's debatable, I get the sense that some people would say that the person ordering entrees should trump the person who only orders drinks, regardless of how much is spent on alcohol. That's not a criticism of alcohol consumption; it's a belief that the restaurant has a primary role of serving entrees, and everything else is secondary, without regard to the economics. I believe that the underlying sense is that using the restaurant for anything other than its primary role is exploiting the rules, particularly when it's for the express purpose of getting a no-charge benefit (the view) at a lower cost. But other people won't accept any notion that the restaurant has any primary role other than profit.
It's complicated, it's subtle, and we'll probably never all agree. But I hope people can at least accept that their decisions have an impact on other guests, without having to agree on whether that makes such decisions right or wrong.