Nor will you see hard evidence on either of your statements, unless Blizzard releases numbers. My guess would be that folks who, for a large variety of reasons, weren't happy with the usual guild thing find that the LFR is enough of a placebo to let them enjoy themselves on some level. It's almost it's own 'thing', seeing that there's a gear requirement to get in, one that is never ever dependent on finishing anything more difficult than the LFR itself. The perks of it outweigh the negatives, so common sense says that many folks have adapted it out of preference rather than feeling that it was their only option.
I'd really like to see numbers on how many LFR raiders haven't even attempted a normal boss in this tier, or all expansion. It'd also be interesting to see how many of those same players have raided normals in the past expansions.