Except since it's a civil case, the most you could do is sue someone who sues after violates those conditions. The judge could rule any way they wish--it's a dispute, not a criminal act, so they have the leeway to make a decision grounded in the law. While the ToS will almost certainly come up in the case--perhaps even decide it, they are not legally binding. One of the most important factors is whether or not the ToS seems reasonable. For example "You agree to allow us to plant cookies in your browser" would certainly be reasonable, but "We will subtract $5 from your bank account each day your account is active." would most likely not be considered as such, unless made extremely clear as part of the website's deal.
Nothing is really legally binding in a lawsuit. I guess you could counter-sue for suing in violation of those ToS, and I'm sure a lot of companies have. You say they can't do something illegal via the ToS, and while that's obviously true, a lawsuit could definitely still be filed over over a legal abuse.
Here's a legal example: You use a stock trade estimation website. In the ToS they sneakily include that "85% of the profit from stocks invested via our Website will go to EvilCorp LLC" or something like that. It's pressed in with a blurb of text. This is certainly grounds for a lawsuit, as you would have no prior assumption assuming that they would take your stock money. They might say "But he agreed to the ToS!" and the judge would probably discard that information.
So as I said, if Pokemon Go did something to seriously endanger it's users, it doesn't matter how maybe boxes you clicked. I'm not saying they are endangering anyone--it's just a hypothetical. The upheld case you linked was a dispute over wireless data charges, something common and expected in the industry. They did not do something unprecedented and malicious.
edited to mention I would not support a frivolous lawsuit
