I actually don't mind these type of topics, as long as they are in the Off-Topic category. What I dislike is when you find something like that in the Debate and Discuss section. Really?! Nail fungus is a controversial topic that may garner a heated debate?!
And when I do answer these topics, I usually try to put in more than a quick "I don't like nail fungus" type of answer. For example, were nail fungus a true topic, I might offer something like:
Being a diabetic, I am more prone to infections. Thus I have to be more vigilant about drying off my feet after I shower, and wearing breathable footwear.
I guess if you do create a topic like this (or answer a topic like this), it should be done more for the actual topic / responses and less about just fulfilling the posting quota.