I think there is also a timeliness to it. 3-4 days is too long. However, I have had to start skipping reading backwards too far as ther are just too many. I try my best though. A lot of the time now, commenting takes longer to write than the post...
I hear you!
People comment on old articles of mine from time to time. A handful of times per week at least, and I usually ignore those.
If I would get 30-40 comments on each article I publish, I'd probably be forced to reconsider my approach a bit too, as it's time consuming to keep up with the comments. But I would never ignore all of them. Not today and not if I had 1 million SP or SBD either. That's just rude as hell.
Before I started to study though, my approach were slightly different because I had more time to invest on Steemit. Since I started to study, I've been struggling to keep up with all the things I want to do, but I'm trying.