There are certainly a lot of regulars on normal tables as well. And even if that was not the case, I cant imagine anything more profitable than playing on a table full of only fish.
It sounds like, its almost some kind of honour / pride thing, that you feel, you must prove, you can beat Zoom. If that is the case, just get it out of your head. There is no bracelet for beating Zoom and especially not at a limit like 5NL. Nobody care about this other than yourself.
For me the only reason to even play 5NL is to get experience and build a bankroll, so that I can hopefully some day play limits, where the money matter at least a little bit. Like maybe 50NL. And if playing Zoom does not help me build me bankroll, it does not help me reach my goal. For me its pretty much as simple as that.
One of the things to remember here is, that there is a very high rake in the micros. So even if you are the best regular at 5NL, unless there are fish in the game, you are likely going to lose in the long run. Its entirely possible, that 5NL Zoom or 10NL Zoom are not even beatable any more except for people, who get lucky over a small or medium sized sample.