the part that I found the most counter-intuitive is that if the casino is over-risking to the point that it expects to lose money, shouldn't it be profitable for a whale to play there?
And...? Don't leave us hanging! How did you resolve this?
I think the way that makes most sense for me, is that the house needs to sort of assume a whale has infinite money. Like if you imagine dragonmaster2's "100% risk" scenario, it's just a matter of time before the infinite angry whale is guaranteed his win.
But if you invert the scenario, it doesn't really make sense to assume you can be a gambler with an infinite bankroll. And with any finite bankroll, all you can achieve is having a very large chance of busting the house -- but you can never turn that into a "profitable" scenario.
So when the house is risking more than a 2x kelly, you have a sort of weird scenario where it's bad for the house (it'll probably go broke) but also bad for the player (it'll still have an expectation to lose)