BlackList

It's their way to vent, I guess, as it's the only thing they can actually do to you. Don't you feel the hurt already?

So my answer to your question was: because... :)

why someone (who don't do giveaways) blacklist other users?

You already answered your own question :

find Someone tries you Hijack another user

Because he can!?

its free game btw

thanks for the GA :)

I got response-black listed by someone who had done only region-restricted giveaways (which I can't join) and 1 public GA that wasn't received. Made me laugh :)

He blacklisted you because you called him out. I don't mean against the rules, I just mean within the interaction. So he's like, "HOW DARE YOU? I'LL SHOW YOU!"

Except he can't. So... eh.

Blacklisted for giving away free games.
https://www.steamgifts.com/discussion/VfGUo/free-gleam-reward-nova-111-500-steam-keys-11-of-11-end

just kidding

It's normal, that the more active one is in the trades/discussions forums, the more blacklisted one gets, no matter what.
For example I've been pretty inactive for half a year, and haven't been BL once. And now that I'm more active again, I get about 1 BL each week for unknown reasons.
Nothing to care much about in the end. However it's a sad view to see the BL graph always right above the WL graph in my stats page.

People blacklist for all sorts of stupid reason. Someone will honestly likely black list you for making this topic lol Some people are just assholes, just ignore them, especially if he doesn't even do GAs lol

blacklists by leeches is the best, they boost your bl counter and you lose nothing :3

I've already got this game, but I will bump your thread anyhow.:)

blacklisting is a way for sad insignificant arseholes to feel important.

I've seen that some russian doing region restricted giveaways blacklisted me, thank You, this will affect me very much xD
Anyway, people tend to use bl for many stupid reason, just don't care about it.. It's a drop of water in the sea, as someone said.