It's like that for me too. I mean, I get likes and comments from my regular subscribers, but some times I get likes and comments from others who aren't subbed to me, but it's not very much or that often as of right now. (a lot of it has to do with the fact that my channel has only been around for 5 months and not too many know about it yet ect) and I guess it could be because my videos aren't *really* what they're used to watching or something or they can tell that I'm still kinda quiet ect (which I'm slowly but surely starting to be less quiet and shy) and that could be pushing them away from my content I don't know *shrug* but OP, it will happen eventually, so don't worry.
For an example: I have another channel and it's not related at all to my current channel, and I have had the other one for 2 years now and it took a long time to get the likes and comments. I got the views, but the other two didn't start happening for a while until one day I started to get a lot of likes and comments and especially the views. So time is a huge factor... it just comes along one day when you don't expect it.