This extreme example points up a basic poker dilemma. You want to make the most of your hands by maximizing your gains and minimizing your losses, yet what are you costing yourself when you play in such a way that your opponents should know what you have? The answer to this question is contained in the Fundamental Theorem of Poker, which states that every time opponents play a hand differently from the way they would have if they could see all your cards, you gain; and every time they play a hand the same way they would have played it if they could see all your cards, you lose.
One step toward winning a big pot is driving out as many opponents as possible. Let’s say you are playing seven-card stud, and there has been a lot of raising on the first three cards, which has created a big pot. You have three-of-a-kind, a powerful hand, and now on fourth street the man to your right bets. You should definitely raise even though you are driving out all the weaker hands behind you.
Indeed that is precisely the purpose of your raise. The pot has become sufficiently large for you to try to win it right now, forsaking any future bets you might win. If everybody folds after you raise, you are delighted. If your raise succeeds only in cutting down the number of opponents, that’s still pretty good.