Whether stake should be able to cast 30 votes, and therefore “control consensus” is a fair question, but considering any changes to decrease this could be simply countered by making multiple accounts sort of defeats the purpose. Imo.

No. Creating multiple accounts would not allow you to circumvent anything, since those accounts would now have less voting power. So if we reduced the max vote to let's say 5. And you still want to control all 20 witness positions, you would need 4 times more STEEM than before. Because in order to get in 20 witnesses you would need 4 different accounts each voting 5 different witnesses.