The all in bet has been a staple of big poker tournaments ever since the ESPN cameras became part of the sport’s reality. There are a number of reasons for this that can be explained from a tactical point of view, but the reality is that the all in bet is exciting: it’s the "Home Run" of the sport of poker, and makes for good viewing. Newer players have been watching this on television for years, and it has become an accepted part of the game. In older days these types of all or nothing gambits were less frequent.
The reason players avoided these type of gambles in the past was because they shifted the game from one of skill to hand where luck would be the final arbiter of how the hand ended up.
What happens before the flop and what happens after it can be as different as night and day. Somebody behaving like a lion before the first three cards hit the board may be reduced to impotent hamster after the flop. Of course this transformation is only valuable if you know they have been neutered and play accordingly. If you have something like a Q-10 or a Q-J, and one of your opponents raises after you before the flop this could have a whole host of meanings.
In the game of poker knowledge is power. This means that the less your opponents know about you the less power they have. So if you can win pots without having to give away any information about yourself, you are ahead of the game. Very few people are going to fold to you just because you have a winning smile so chances are you’re going to have to play some poker in order to get your opponents’ money. Every hand you play is a potential intelligence gathering exercise for the rest of the table, so there will be times when you want to hide behind somebody else during a hand. In short, you need a Trojan Maniac.