What makes you think there wasn't a complete background check?, I don't know how you can rate his coding skills (much less say that he lacks others) but having worked with him I realized that he is really committed to the players (trying to give everyone a great playing experience), has an excellent work ethic and was overall a really nice person to work with.
I also remember the times where Guinsoo and Eul where in charge of development (not fondly) and in my opinion it's thanks to IceFrog that the game achieved it's current popularity, even while developing DotA2 he still delivers new versions with new content regularly to the community.
Disclosure: ex-Forum Moderator dota-allstars.com,playdota.com ex-Beta Tester
I wasn't saying I think there was no background check, just that that would be a plausible explanation for the hire. And by background I meant the background of DotA, not IceFrog. I'm quite sure he's not a felon or a KGB spy.
About his coding skills, see my reply to MrJagil below. About art and other skills: IceFrog didn't create any of the art in DotA. It all came from community sites (wc3c.net, hiveworkshop.com, the now defunct war3sear.ch, etc.). The game design was overwhelmingly done by previous DotA maintainers and the DotA community via the sites you moderated. Even the tools on which DotA depends for its life (in particular The Widgetizer[1], without which, as a practical matter, DotA can't be loaded because it has too much object data) were all made by other people.
This is why Valve naming their game DOTA 2 and attempting to trademark DOTA has angered so many people, and why Blizzard is now going after them. DotA isn't IceFrog's to give, which Valve should know if they did any research into its history. But because they're Valve, people on the outside don't seem to care. If it were Microsoft or EA, I'm sure we'd be having a very different discussion.
At this point, no, I don't believe it is. There have simply been too many people involved, too many fingermarks in the clay. Even if Eul, Guinsoo and IceFrog teamed up together, Blizzard would still have a valid claim.
> who is also a Valve employee.
I also don't really believe this. People keep repeating it, and the source is always that same, single, ambiguous sentence of Gabe's. Hopefully some real information comes out during the trademark litigation.
I also remember the times where Guinsoo and Eul where in charge of development (not fondly) and in my opinion it's thanks to IceFrog that the game achieved it's current popularity, even while developing DotA2 he still delivers new versions with new content regularly to the community.
Disclosure: ex-Forum Moderator dota-allstars.com,playdota.com ex-Beta Tester