How I would say it is:
If SOF people were really nice, then no one would have been down-voted.
As soon as I joined SOF, as many others I am sure, I got a few of my questions down-voted, my "Hey guys!" removed, and a bunch of other weird-to-me-at-that-time stuff happened.. That made me really back-off from SOF. I wasn't back till I read around 50 QAs and the FAQ, like 10 times.
Then, I wondered.. Why would people down-vote? Why not just answer the kinda-dumb question? Why remove my "Hi, guys"!!
I have just recently became active on SOF, and finally found the answer:
One day, I answered a question that was kinda dumb, and there was a guy who kept complaining that I shouldn't answer. He didn't make it clear why the question was dumb, nor answered for that matter. I completely ignored him, and got an accepted answer! I thought, "Hey, if that guy was so smart, he'd answer this dumbly-easy question instead of all that complaining" ... Next thing I know, the question gets deleted, and the rep I earned gets taken away :/
The other point, removing the "Hello!", turns out you get rep for editing questions...
(Some - Many - Little - Most [You decide]) of SOF users are not nice, and won't bother help if they don't see personal benefit. Aarobot's answer is great, and agrees with that. I am sure you see why by now.
As for me, the guy who accepted my answer, before his question got deleted, told me something like:
@Mazyod, thanks for realizing my point.
I know we are not raising charity here, but it won't hurt to lift the spirit of some random guy instead of just complaining. That guy was kinda evil, let alone not nice :p. (Maybe he was having a bad day, idk...)
Now, I just hope this isn't flagged as a duplicate answer or something .. There is no such thing here, right? I just expressed my POV which supported Aarobot's answer..