I think the point the poster you're responding to was making is this: If people lose their money quickly to bots/collusion/cheating (or simply skilled players), they will quickly run out of money. If they play each other, they can play more hands, so more profit for the casino.

To exemplify the two extremes, assuming 10% rake: Player A has $10, and loses $1 every hand: after 10 hands, he's broke and $1 went to the casino. Player B and Player C are equally skilled and equally lucky. They keep playing $1 pots, trading back and forth. After twenty hands, both have still have $9 while the casino already earned $2. They could essentially keep going until they have given all their money to the casino.

Well that is how it works. The casino provides the service of collecting players together to form a game, serving a fair platform for them to play on, ingesting and disbursing funds (which is no small matter), and then attempting to prevent them from cheating each other. That is the business model for poker, and it's extremely hard to make it profitable. If you factor in the time it takes to do all those things, as well as managing the software 24/7, it's a wonder anyone bothers to host it at all these days.

[edit] As an individual player, obviously, whether IRL casino or online your goal is to outpace the rake. You factor the rake into your expected losses and find a casino with a low rake (ours was actually 3%) and try to get away as a winner. But of course as a casino owner I love grinders and they're who you want day in and day out.

3% rake is amazing. Where's that?