A dynasty is always good for the sport from a ratings/money point of view. The casual fan is always more interested when there's one team or player that dominates. They either root for them or against them but there's certainly more interest.
From the more serious fan point of view it's only generally more interesting if you're a fan of the dominating team/player.
So my basic premise is that whether it's good for the sport or not is in the eye of the beholder.
SW and others who have made similar points could well be right. But isn't it possible that the real ratings boost is an intense rivalry like UConn-UTenn in the olden days or UConn-ND in more recent times? Yeah, ESPN and print will talk up a streak as it gets close to 88, but that's once every three years at best. Rivalry games in the regular season and often the playoffs seem like a more consistent path to coverage and fan enthusiasm: everyone gets to pick a side AND have a reasonable expectation that their side could win.