+1, kill functions only make sense in contracts which are expected to operate within a specific narrow time window that is governed outside of the contract.

For example, a fundraising period. Kill functions work well when you can effectively say "oops we screwed up the event window, we're going to relaunch with a fresh event window."

For something that is intended to exist permanently, the kill function is strictly harmful as it creates risk for anyone depending on the contract (unless your intention is to avoid having people depend on it, I suppose).

I don't like the concept of a smart contract having an "owner". Why should anybody have any more power than anybody else?

A true trustless smart contract would have no owner.