Well, when you want to see jacks-of-all-trades, watch some MMA.
But when you want to see a master of a particular skill - watch that particular art.
I don't have a problem with either, it just depends on what you want to see at the time. If I want to see some really high-level boxing, I'll watch boxing, not MMA. If I want to watch shootfighting takedowns, I'll watch MMA.
There's a trade-off here between scope and depth - and there's nothing wrong with that.