*Sigh*
Yes, this issue has been discussed many times, especially since 3.5 came out and the rules changed. The math behind the feat tends to surprise people.
Here are the most important pieces of info:
1.) Power attack is often poorly used, at least during a full attack. Many PCs use it to drastically increase their damage per attack, but fail to properly account for the number of misses that result from the use of the feat, especially with their second, third or fourth attack. The truth of the matter is, unless you're hitting very easily with your worst attack (or are having trouble hitting at all with your best attack), you're unlikely to want to power attack for much, even with a 2 handed weapon (if your main goal is to increase your average damage per hit versus a set AC.) This means that the only times power attack really helps you out is in situations where your foe is pathetically easy to hit or is incredible hard to hit - which should be rare circumstances.
2.) Power attack requires information to optimize. If you don't know a foe's AC, it is very hard to know how to optimize your PA. As a result, the number of times a PC actually gets the maximum benefit out of power attack is rare.
3.) Power attack is most useful in single attack scenarios (slowed, attacking after moving, when you can't attack except for AoOs, etc ...) instead of full attack scenarios. In those instances, it is fine for a fighter to do an obscene amount of damage with one hit as it will be his only attack for the round (with the exception of AoOs).
4.) The math behind optimizing PA is complex - more complex than any of the models I've seen thrown around in the past. Death from massive damage, attacks of opportunity, the total hit points of your foes, etc ... are just a few of the variables that I've rarely, if ever, seen discussed in those models. And I've never seen one that takes into account all of them.
5.) If you find that in your games, the fighters using PA are getting all the action and the wizards, sneaky rogues, etc ... are not being effective, you may wish to revise PA. If not, don't worry about it. For most games, it will not be an issue.