Little gag replies are risky here. Potty humor like what you've done above will never be rewarded. It's too easy. Sometimes clever puns or double entendres will get a couple of upvotes.

This is the correct behavior. Everyone is capable of making little gags, so they add little to the OP. Not a downvoter, btw.

The problem is that it's hard to tell humor from this https://news.ycombinator.com/item?id=7862743

Also: Rule 34.