Where did anyone ever mention going and losing $500 to a top pro? Can the person who might potentially lose this money even run a rack?
If that's what you think people are talking about when they say gambling to learn, you are missing the point completely.
Yes, instruction facilitates the process of learning pool. No doubt about it.
No one is saying that lessons with someone who has a wealth of knowledge isn't going to get you to the next level.
But when push comes to shove, if you are in your room playing better players for 20 bucks a set, or 5 a game (AFTER you have SOME semblence of a game), or whatever sized bet actually puts the pressure on you (could be 2 dollars for all i know) In the long run, you are going to do better in the pressure situations then you used to. Your game will improve, as will your confidence in the long run, as you begin to understand your capabilities, limitations, and what you are capable of.
If it DOESN'T, then you will realize that you are one of those people who CAN'T hack the pressure, and you will save yourself the agony of trying to compete when it isn't in you to do so.
Pool is about competing, and as such, you need to compete against other players. Learing about it is NOT enough as you will ultimately fail when put under the gun in a pressure situation.
Only by either gambling (and we're not talking about taking out a second loan on the house, and blowing it)with someone slightly better than you, or entering local scratch events, can you experience the pressure you will need to overcome. As you play people better then you, if you are good enough, you will eventually beat them, and move to the next better than you level player to compete against.
Gambling just makes you get over that pressure hump all that much quicker, and you need to be the one who determines what level of gambling is gonna do you the most good.
If after you've come along, and feel you are at a higher level in pool, and want to test yourself, THEN you might think about taking a couple of barrels and aiming them at a higher level player to see how you do.
But to go and dump the money before you even know what your doing is just ridiculous.