I agree, but we have a problem when a captain could (theoretically, this hasn't actually happened) just say "alright, I'll deliberately slow down the overs and cop my fine/suspension in order to win this test". That's a problem, because the result has still been unfairly altered, even if the guy cops a one match ban afterwards or something. It's kinda like the chucking thing, it's all well and good to impose a ban after the fact, but if the person breaking the rules alters the course of a match, you've got a problem that needs an on-field fix.
So yeah, I think if they are going to get serious about over rates, like with apparently threatening Ponting with a ban during the break yesterday, they need an on-field solution with actual repercussions.