I think anyone that hasn't paid attention to Bellator is really missing out. I also think that anyone that watches just the UFC is really missing out. It's almost like the people that refer to MMA as UFC. Bellator is a great product with great fighters and right now they currently have the best LW on the planet fighting for their promotion.
Some of the best fighters in the World are in Bellator and if it wasn't for contract BS the UFC would snatch up a good number of those guys in a heart beat. There are plenty of fighters in Bellator that would be instant contenders and instantly in the UFC top 10 rankings. Anyone that thinks Michael Chandler and Pat Curran aren't elite world class fighters doesn't know what they hell they are talking about.
I don't think it's about how good fighters are or not, it's about the amount of time someone wants to spend watching MMA and how well known the promotion itself is.
Casuals certainly aren't showing up to watch it, all they know is the UFC or perhaps all they want to watch is the UFC, it's the NFL of MMA after all.
There's a good portion of "hardcores" who don't watch it either like myself, simply out of the fact that our MMA time is better spent in the UFC than elsewhere. There's tons of divisions in MMA now, tons of fighters, tons of events from PPV events to free events, it's a lot to cover. Especially when you have other hobbies/things to do that take up as much if not more time.