The only thing that directly influences how much CFB I watch is availability: is it somehow available for me to watch/consume?
If every single CFB game were available for free on my TV, I would watch A TON. Start with my schools, then work my way outward: conference foes, conference title implications. From there, maybe some secondary schools and/or anything that plays into the national title chase. Maybe a generational talent that needs to be seen before moving onto the NFL. Reggie Bush was the reason I watched USC years ago.
That (100% availability) is hypothetical, obviously, and would never come to fruition.
Realignment plays into broadcasts availability. Basically, it has an indirect impact on how much I consume.