I think both N-zaps see equal use in Rainmaker, i mean just the other day i saw a team with the 89 and the 85. You know how it is, the N-zap 89 gets used more in splat zones than the 85 because the 89 has better turfing capability than the 85 (But the 85 is still great at turfing.) The 89 has Inkstrike which you can use to clear the tower on TC or temporarily block a path in RM. It can also capture a blackbelly splatzone, and cover just enough of most other zones in some other stages (not all stages though) to make the counter stop. The 85 can be useful with it's Echolocator, and splatbombs are hardly a waste on this weapon, it's great turfing ability allows it to be a speedy zone taker, Echolocator really helps in tracking your enemies letting you know if someone's preparing a sneak attack, or where they're hiding...
As i'm not an N-zap main, what i described is probably only scratching the surface of the potential of the N-zaps. I do not believe that they are "snubbed" based on my encounters. As i see them every so often quite equally. That's from my experience.
The Nosslenoses on the other hand are "Snubbed" because of the high skill that they require. Though in all honesty, after playing with the H-3 Nosslenose then some of the L-3, they're quite deadly weapons. The L-3 is much easier to handle despite requiring "Impeccable timing" to keep a constant fire, but you don't reeeaaaallly have to be frame perfect (You can if you want though), it's fire rate allows for some speedy splats even if you miss a burst (or if you're like me and can't be frame perfect, you can still press again fast enough to warrant a splat). Plus it's Turf covering ability is pretty awesome as well. Disruptors on a weapon with range almost being equal to the 96 gals like this are a god send (You know, they slow down like a snail, become easier to hit, but they can still fire back at you though). And the Killer Wail is pretty decent too, holding off the enemy spawn, clearing the Tower, firing at Port Mackeral, it has viable uses that are pretty useful if you ask me.
If you run the L-3 D you'll find that getting a Kraken with the L-3's fire rate is not as hard as some other weapons (Like the Custom Range Blaster) so the Kraken is absurdly good on a weapon like this. Also it's a panic special, so you think you're about to die? Nope, Kraken. Alot of people get annoyed by this (including my self) but that's just how it is. Oh yeah and burst bombs are easy to throw around if you want to poke people over the other side of the walls, just don't get trigger happy with them, they're probably not as good as disruptors but it's a good asset to the weapon.
The H-3 on the other hand is hard to use when you don't run cold blooded and come across an echolocator team. (With the number of E-litres out there, this can be pretty common.) The H-3 succeeds when it gets a successful burst kill where all three shots hit and they go "Splat". But getting this burst kill is hard if the enemy knows where you are, because they could just literally step to the side, and you'd have to make two bursts to splat them. This wouldn't be so bad if the H-3 had the L-3's fire rate, but it doesn't, and it's really unforgiving against the 96 gals if you miss your shot because they can easily take you out once they see you. Against most other weapons, a missed burst usually means you have to retreat, or against the shorter ranged weapons, you might have the chance to get a second burst, but after that it's retreating time.
(Haven't played with the H-3 D as much so i can't really talk much about it. apart from Inkzooka's nice, and Pointsensors are handy)
TLDR you'll find that the Nosslenoses are quite deadly weapons in the hands of great players. Also i might add that while the Rapid Blasters don't typically see quite enough use, i still think that they're really good.