Most spammers are poor in terms of Steem.

The majority of spammers I find almost no Steem due to the low rewards they get (I see spammers posting 30 times a day for 1 cent per post) and the fact they are always powering down and selling.

Have you seen this?
https://account.steem.ninja/

$2 USD (Via Credit Card) to create new accounts, including 15 SP delegation for 90 days. This is a great on-boarding avenue as well. Paying for accounts even if it is only $2 USD is not ideal, but it is a big improvement.