I don't know how many different ways I can say that your abuse/war-of-the-roses scenario isn't the problem in EVERY divorce. For extreme cases like the ones you are fixated on, divorce would be available even under a fault-based system. For the LESS extreme cases, the ones that you seem to ignore, a less permissive divorce law would keep people from splitting at the drop of a hat because the party who wanted to leave would have to bear the economic cost and loss-of-custody cost of the breakup unless they were leaving for a good reason (e.g. abuse, infidelity, etc).

My political ideology is basically libertarian (although I'm not a utopian). For me this isn't an issue of increased state interference in personal relationships. The state is already up to it's elbows in marriage/divorce. In a divorce, absent mutual agreement by the parties, the state dictates property division, child custody, and future support payments. You can't get much more involved than that.