I support the idea of limiting the amount of memos by the reputation level. Wouldn't that then restrict the amount of memos with older bots as well as their rep could be low because of people flagging them as spammers? Or are they too big for that?

The idea of memos costing at some point it also great. I have no idea why a regular user, not a spammer, would have a reason to post so many memos in one day anyway.

Good suggestions both, but as always people and spammers do find other ways. For example creating endless amounts of new accounts. Maybe buying existing accounts and turning those in to spam accounts. So the connection between different accounts and what does it say on the memo is also vital information and maybe that could be used to restrict spammers also. And I'm sure something has already been done to that.

The blatant comment spam may also have decreased because steem value has decreased. Even spammers have to spam harder in order to get their days profit. :D

The uneducated spam could be those who have heard and understood that one needs to comment in order to get noticed here. But the fact that one has to find original things to say seems to be too hard for them. And sometimes for me too. It's hard to comment something original in English as it isn't my native language. But as everything, it does get easier when I just do it more. Practice makes better. So I tend to go easy on those who have upvoted my post and commented something not so original if I know that English is not their first language. If they have not upvoted me, only commented something like nice post, I do nothing. Usually don't even bother to visit their profile.

P.S.
I liked your post, I would give you my upvote if I wasn't in recovery phase with my voting power. It seems that I've been upvoting little too much lately. I take it as a good thing because now I have to comment instead of upvoting (normally I'm too lazy or I don't have the time to comment) and that forces me to be social. :) I'll upvote you next time.