Interesting thread. I hadn't thought about it, but I think I am like you, Lisap—there's something about them that gives me a knee-jerk frump reaction.
However, I will also say that I avoid all hose like the plague. I absolutely hate it. So I have no hose, except maybe one black pair from, oh, 15 years ago. I would like to buy a pair of the nude fishnets, though. I think those are interesting enough to not be frumpy.
When the weather cools off, I wear tights. I buy tights with a high natural fiber content (not nylon tights), so they are very opaque and textured. These let my body breathe so I don't sweat so bad in them; I don't find nylon very breathable.
I had considered buying some knee-high nude hose for wearing with pants and flats for days when the weather is cold, but given the breathability issue I have with nylon and also given my fear of frump, I just can't bring myself to do it.