You miss the point. The Fighter doesn't need the feat and can spend that slot of something else while the Dwarf likely wants to spend that feat. I don't think it would have been accepted very well to have the feat with a text wall of prerequisites even though some my have preferred it to be that way.
Why does the fighter (with already good stats) not need the feat? Because he already hits enemies on a 10+? Wouldn't it be even better to hit enemies on a 8+?
That's what I don't understand, here. Once again - let's say we've got a dwarf fighter. Lower Str, lower proficiency weapon. He hits enemies on a 12+. We've got another fighter with better stats on hits enemies on a 10+. You seem to feel the dwarf fighter needs the boost from Expertise to stay viable - that the difference of +2 to hit really matters between them.
So why doesn't it matter just as much for the other fighter? Why isn't it just as much an improvement to hit on an 8+ instead of a 10+? What other feats could possibly be more important than +2 to hit?
Now, at Heroic levels the bonus is only +1, of course, and I agree that other choices may be more important. But by the time it reaches an unconditional +2 to hit, Expertise has been better than everything else out there.
And I simply can't understand any viewpoint that can insist it is useful for bringing lower accuracy characters 'in-line' with more optimized characters.. while ignoring the fact that optimized characters will take it as well, and the same difference between the two will remain. And, more importantly, other non-optimized characters
won't take it, and the difference between them and optimized characters will only grow larger.
Again, it's not necessary in a number of cases because it isn't a "huge hit" to power. With normal stat distribution, good tactics and leaders/controllers with a clue hitting generally isn't an issue unless dice get very cold. Boosting durability, defenses, damages, etc. are often more important. Sure, if you want to ignore party composition and try to play all strikers or such then it becomes more important but with normal role spread it generally isn't a big deal.
What do you mean by "hitting generally isn't an issue"? Keep in mind that most abilities used by all classes rely on hitting to really work - automatic effects are usually the domain of daily powers, and non-attack powers are few and far between. So, yeah, hitting is pretty important.
Do you mean that people already hit just fine? That seems to be your indication... but I'm guessing your party doesn't hit all enemies on a 2+. In which case, yeah, they still will be missing on attacks. Increasing accuracy by 2-3 points is going to be a really big deal, regardless of class and role. Now, are other elements (durability, defense, damage, etc) also important? Sure. But rarely will you find a single feat that offers enough in those other areas to compare to what expertise offers for accuracy.