I think the answer that most of us would agree to is "it depends". Paint does 2 things: it protects the frame from rusting (steel frames, that is), and it is an artistic expression of the bike. I think a good topic for discussion would be a "before and after" paint thread - post your pics before and after, and have a poll on a scale of 1-5 of worse to better to give a glimpse of what others think. Hmmmm, how would that poll work? The tools available on this site would be one bike, one thread, I would think.

For example, @Lascauxcaveman posted two bikes where I completely agree with his decisions. the Grandis has a few knicks, "beausage" comes to mind. The Lambert, on the other hand, is in need of new paint.

This poll wouldn't invalidate the person's decision, but would give some insight into resale value, perhaps?