As someone making his full time income from game development for the past several years, the common wisdom among developers is that there's a handful of commercially successful games on XBLIG (which is not the same as the much more successful XBLA) & that you can pretty much discount that as a profitable option if you intend on making a commercial indie game.

It is simply a lot harder to make money on XBLIG than on Steam/app store/play market.