If you look at what Microsoft has actually said about it's gaming division it has lost a lot of money that's yet to be paid back. (Not to mention plenty of internal cost shifting that makes things even worse.) Based on the size of there investment in both R&D and other company's it's been a horrible investment that's unlikely to ever be paid back when you include basic opportunity costs.

If you really want to look at sales, games are far from the only revenue source, accessory, downloads, XBOX live are all significant. Nintendo has made a lot of money reselling legacy games. They may be cheap but there is no R&D costs and they get everything not just a tiny slice of a 3rd party game.

As to loyalty, that's next to non existent in the console market. You get a slight bump on the next generation and that's about it.

PS: From a pure ROI standpoint Nintendo crushed the completion this round. Unfortunately the Wii U does not seem to be making the same headway.