I agree, stake-weighed voting is one of Steem's key selling points.

A bad actor would have to purchase an insane amount of Steem (and put a lot at stake) to cause disruption. And even then other Steem holders can get together to negative the bad actors influence.

Gaming an Account based system is easier, less costly (in my view).

We'll see how it plays out if there is a successful SMT that is account-based. From what I understand Steem will remain stake-weighted, which is a good thing.