No, not spam. I hate spam with a passion, this doesn't even to begin to approach that. An annoyance perhaps...but no where near the level of spam
Is it good etiquette ? No. Would we all just appreciate a follow up? Certainly. But imagine someone who is having a problem, searches Google for somewhere to get help. Never been on a forum before. Joins several and posts the same question on all of them. Maybe he finds some help on one and sticks there. He doesn't return to all the others...likely didn't even note where he posted.
It's a quite common scenario. The idea that every one of them did this to irritate people is very unlikely. They just want help, and have no idea how to ask for it correctly, what info is needed, how to compose their question. Just imagine someone who is clueless about the whole situation, and just posts what they feel is the major issue
A Guy