I imagine it's mostly just playing the percentages. Bet when it has a high percentage of winning, fold when it doesn't. It doesn't need to read its opponents if it can play the percentages perfectly.
No, this is a terrible idea. If you play like this consistently, you are basically telling your opponents when to play against you and when to get out of the way. They can even pick bet sizes (assuming no limit) to refine your possible hands very accurately.
I'm usually surprised in tournaments by the number of people willing to play with me after I've sat quietly folding for the first three rounds... By all means, everyone should fold and give me the blinds, but there always seems to be a player or two who bite!
This is a very naive interpretation of the game of poker. Professional human players are already very good at calculating the percentages, and any joe playing from his computer has access to a calculator.
The reason why simply playing the numbers fails is that if I know an opponent is playing this way, I'll just fold every time he decides to play.
This is true for Limit Hold'em, but very much not true for No Limit. Limit Hold'em is a solved game, because as long as you're playing the odds, you can play perfectly. No Limit changes things because the bets can vary wildly. If you play a tight game (just play the odds), and opponent will get out whenever you're in, and will bluff just to see if you call or fold.
Bluffing is a major component in No Limit, and there are very different profitable playing strategies.
I fell to this when I randomly decided to play some limit hold'em one night. Kept losing to a guy that chased every chance at odds he could, because I couldn't make bets big enough to scare him out. Lesson learned!
That's not true at all for limit, the perfect bot's bluff frequency is probably higher than most humans. Play against it yourself here http://poker.srv.ualberta.ca