Originally Posted by Slayer Lord
You're right, but that's also the point. It's never good when all the significant problems are solved by a single character, no matter who it is. Like LaZodiac said, "But if Orihime gets to do something, Ichigo doesn't get to do something. So we can't have that." And the sad thing is, you can substitute Orihime's name for any other protagonist character and it'd still be true.
It wouldn't be so bad if Kubo gave us a consistent and believable reason why she can't solve everything (or help out in fights at all, for that matter). Instead, he keeps coming up with reasons to shove her (and everyone else) off to the side so Ichigo can be the big damn hero. Hell, Ichigo might have been in a condition capable of at least standing up to Nnoitora if he hadn't been all, "Keep your helpful support magics out of my fight with Grimmjow, lady. This is a fight between men." Though this baffles me more for the fact that Ichigo supposedly came to Hueco Mundo to RESCUE Orihime, not brawl with his personal rivals.
So? Orihime is silly and useless. She was before she got powers, and she still is with them. She'd still be useless even if she was stronger. That's just her character. She's not useless because of her power level...she's useless because of her personality.
Ichigo is pigheaded, arrogant, and prideful enough to do exactly what you're describing. Besides, involving Orihime in that fight would have made her a target...which is the last thing Ichigo wants. It's not an optimal decision, but it's perfectly in character.