Players who specialize heavily in combat are better at combat--that's a feature, not a bug.
And what's the point in allowing players to specialize heavily in combat? I mean, it's very reasonable to allow specializing in a combat role, or in a style of fighting, that doesn't create any inbalances in the party because each character shines in his own niche. It's also very reasonable to allow specializing in a non combat skill or feature, again each character has chances to shine. But what do we gain from allowing character with same level and class but significant differences in to hit rolls? Why would that make the game more fun? Because, you know, if somewhat insists in playing a weak character for the sake of it, he can always stay at 1st level forever.