I always sharpen hooks, maybe not right out of the package (I ALWAYS check them though, even brand new!), but eventually all hooks become dull. At that point, it doesn't matter how sharp they once were, or how they were sharpened at the factory. That hook point is long gone, so it doesn't matter anymore. You can't "ruin" the factory point once it's dull, so sharpen away!
Yes, I sharpen even Trokar and Owner hooks once they get dull. I can always get them razor sharp again.
I'm totally mystified why people won't sharpen a dull hook because "it will ruin it". To that, I say, "How's that dull hook working for ya?"
Sharpen it!