✨🤔 ✨ Is it proper to upvote people's comments to your posts ✨🤔 ✨

Hey fellow Steemians, 

I was just wondering what everyone's view is on upvoting comments that other users leave on your posts. I noticed that some of the Steemians that I follow with lots of SP (no I'm not gonna snitch) seem to only upvote their followers comments occasionally and seldom engage with them or respond to their comments., while those with relatively low SP are more gracious authors it seems. 

I was just wondering if this was commonplace or if I am just following the wrong people.  What are your thoughts on the matter because I'm kind of confused and feel I might not be utilizing the platform correctly, or may have the wrong idea as to how to interact with people on here. 

thanks

Edit**** I try to upvote all comments on my posts.