Ah, that makes sense, question answered.

My second question is that if bongs and water pipes are the same thing, why does the law distinguish their purpose by their name? It seems like given "I want to buy a water pipe for smoking the marijuana" and "I want a bong to smoke tobacco", the second should be legal to request, not both.

intent determines if a thing is illegal. If you intend to use that bong for weed it’s pariphinalia and a felony, if you intend to use it for sheesha it’s fine.

if you intend to use that power tool or crowbar to break into a house it’s “possession of burgular tools” and a felony, if you’re a contractor there to install some drywall it’s not.

_bong_ is considered drug slang, water pipe is not.

I'm pretty sure it's CYA more than anything. The DEA is very aggressive and raids like it's going out of style