I blame Angthoron, as I too asked for a non-Steam version, and got a Steam one. Eh, I'll live, it will be one extra copy I can sell or trade or give away.
I'm actually quite annoyed with this. I ordered the non-Steam box and the Steam key, on the assumption I would end up with both versions. Instead, the box version is Steam, my key is Steam.... and the extra key I get with the game is ALSO Steam. If I had even known about the extra key I would've just ordered the original key for GOG as an immortal backup, and gotten both anyway. Instead I'm stuck with three Steam versions. Yeah, thanks.
It would be nice if there was a way to convert Steam key into GOG key, or something. Or just get both versions. When I got FTL from the developers' website I got both a download link from them AND a Steam key, which is always nice.