Minecraft is a game with so many updates you definitely want to receive, if you are pirating it then eventually you'll give in and buy it because it's a PITA to keep re-pirating it every time there's an update. Or at least that's what happened to every person I know who pirated Minecraft to try it out.
@brianna if you have a cracked MultiMC launcher you get the updates on release day instantly like everyone else, actually.
and it is available publicly on github for all platforms :P
I think people just take a sketchier route with it than they need too.