I'm not sure that DVs are used as much as you suggest. Most people won't get them and there's no big incentive for big accounts to drive people away as that devalues the platform. A few people do get slammed, but that is usually down to bad behaviour (with exceptions). It can also be just people falling out.

I do think that DVs should not be used on new accounts unless they are obviously scamming. People need to understand what is acceptable and a comment on that may be enough.

I expect a lot of people give up when they don't make much immediately and something else gets their attention. They will go where their friends are.

Hive is imperfect, but still better than a lot of other platforms.