This is evolving into a discussion of depth versus breadth.
And in general, in any RPG it is much better to be a master of at least one thing than to be OK at a lot of things. One reason for this is that you are part of a team, and if you are just OK at a lot of things, you'll typically always find that someone other than your character should be taking the lead role. Another reason for this is that it is usually much more costly to get good at many things than it is to get really good at one thing, and as such a big hammer that can treat every problem as a nail is typically better than a partial tool chest of specialized tools that are only usable in some cases and cost as much as the big hammer without solving any problem well.
However, in my experience "power gaming" that is strictly depth only is something that is actually going on unwitting cooperation with a GM, because the GM is pretty forward a series of nails to hit and wondering why the players only develop hammers. A lot of power gaming can be mitigated by good encounter design and good campaign design that gives the power gamer a reason to want breadth because he sees how mitigating his character's weaknesses is every bit as important to survival as developing his character's strength. A good GM tends to hit you just as much with the question, "If this character is going to die, how is that going to happen?" or "If this character is going to feel unheroic, when will that happen?", as questions like, "If this character is in a damage race, how will you assure he wins?"
This feat is a 'breadth feat'. It gives options at a low opportunity cost to classes which don't have a lot of weapon options. For them, it's equivalent to +1 to an ability score AND +1 to damage dealt.