I know many hive users that have never even used bitcoin before they earned Hive for the first time, not many cryptos, if any can say that.

I am one of these people and this is a super important point that many miss - Hive has already bridged the gap to the mainstream, it just needs to be networked outward.

How about a way for investors to “opt out” of curation?

Hive account@edicted has been talking about using the "savings" function in the wallet for this. It is a good idea and shouldn't be hard too implement. I and others have talked about staking returns outside of curation, so that a user can stake, get a pretty decent return, but not be able to use that stake to alter community functions. Using the wallet could come with other limitations, for example not being able to use that portion in the wallet to vote proposals or witnesses - - but they can still have the shortened unstaking period (currently 3 day) of the wallet.

Lots of ways to tweak and yeah, I think getting rid of the comment curve might be a good idea - I upvote pretty much all comments I get, but not many do as it is far too expensive in op cost to do so.