As others mentioned, it is all about footprint - recruiting and viewers. That is what drives realignment, not sanity, and certainly not any fan sense of what would be appropriate or even remotely interesting. With that criteria, the B12 gains nothing with HOU, but MEM, CIN and UCF provide viewers (and for UCF there is the recruiting benefit for playing games in the heart of Florida). These are all weak sisters, and do not threaten the TX-OU domination of the conference, but do increase revenues (viewers), so it could happen.
Putting aside the real decision points, I could see MEM and HOU are the hot options, but I don't see either as a sustainable program. Both have had rumors of losing their coaches to P5 schools. Joining the B12 still won't make them a P5 school and those coaches will likely get stolen. At which point, these weak sisters lose any semblence of threat and become the ASU of the P12 or the ILL of the B1G. From a football and competitive standpoint, HOU and MEM are your best chances to add some strength to the conference, but as soon as the coaches leave, you've lost that aspect. BYU brings a fringe program, but it will not help recruiting, and besides the Mormon Nation you won't be gaining a lot of viewers (assuming you absorb the BYU network....yeah, set a precedent for the Foghorn Network, yeah!). But ultimately, you are signing up another weak sister, one with some weird idiosyncrasies that you may regret later.
The B12 won't pull in any good programs, there just aren't that many out there and even the crappy ones (MD, MIZZ, RUT, etc) have been taken into P5 homes. If anything, the B12 loses OU (and maybe OSU) to a better conference and is left collecting even more weak sisters. They (TX, and the others by letting TX be TX) put themselves in this position, let them eat it.
