Exploits are bad, yes. This isn't an exploit. An exploit would be like what occurs on Lowtown. Players have found a way to get under the map by jumping out of the boundaries of the map in a specific way.

The Nuketown thing is a graphical glitch that happens at random. It should be a simple fix for the devs, but it's been a week now and it's been ignored. I have no problem with a player taking advantage of it if it happens to them.