I was talking about this topic from a different angle just the other day, instead of removing inactive followers, I rather treat the followers number plus not give it any value.
Why? because automatically removing inactive ones (without also harming legit users by error.)
Making a button to remove followers you don't want (as in block a user from following you, but not blocking their posts/comments) may be a good option I'd like to see, but most of the people who want a high number of followers won't use that function if it's there.
Followers aren't a measure of success, the follow function is there only to let you put interesting people's post in your feed, I don't know when it became a measurement standard.
It's hard to solve this problem, and even if now it's isn't problem in future it will. I wanna have big number of followers but I prefer real ones because this are people who can give me power here. With gaining big numbers and nothing else like 100k subs, and 3-6k views per vid, it only can gain frustration.
I think that maybe we should have another think like bell on Youtube, If somebody wanna be 100% followers he should choose bell icon?
there is another problem, because on youtube you can have 20 people with name Mardax, but here not, and fake account's registers names so somebody will be forced to use name "imann2321323123213"
I wanna see here a bigger picture. If steemit wanna be a big social page we need to prevent from fakers, and bots ect, or we end up like YouTube facebook ect, and then people will run to another site project like Steemit because steemit becomes what we wanna ran of.
If this gonna be like this forever I should go somewhere else. I just wanna have health audience.
that's my thought.