It is a odd that it's going right to MOD, that's usually for older more niche stuff. I've never seen a brand new release go straight to MOD.
it's quite possible that sales haven't been high enough to justify a full production run for the second season.
Do we know what broadcasts are BL are like outside of the U.S? It's never had an FTA or cable broadcast in Canada (not sure if it's on netflix). With a smaller audience, the number of people who will buy the dvds or blu-ray are greatly reduced. For example if it aired in Canada it would increase the demand for home media in the same region format as the U.S.