I asked my better half about this, because I'm a newbie as you know. I'm not saying she's an expert, but she was a pro cook and spent many, many hours doing prep work.
I'm paraphrasing here, but basically she said most knives don't even need to be sharp enough to cut tomatoes. There's no reason a knife needs to be sharper than necessary to complete the given task. She also said with a very fine edge, you're more likely to bend or knick the edge, and that, all other things being equal, a "less-sharp" edge is going to be stronger/more durable than a razor-fine edge.
I'm not arguing knives should be dull, but unless you're shaving with it, I don't think there's anything inherently better about having a razor-sharp knife.