I agree about comments are important for engagement, but then that was always the number 1 rule for growing brands on social media isn't it? Post interesting content for your followers then engage with them, and make an effort to engage with other potential new followers with similar content.
And the comments I receive might not seem much, but they are still infinitely better than the levels of engagement I received on other sites. They at least prove that someone has read my content and found it interesting in some way.
I try to leave as many comments as I can... but its not always easy. Just as it takes time and effort to write an interesting post, it takes time and effort to write an interesting comment. And I refuse on principle to leave a Nice Photos! on someones post. If I can't think of anything genuinely interesting to say then I don't bother. The interests on here are SO varied, that I can't have an opinion on everything... If someone makes an interesting post about cactus plants (or whatever) I can vote to reward the effort of sharing the interesting content, but I have nothing useful to actually add to the discussion of cactus plants.
As a quick tangent:
It does seem to me so many people seem so determined to 'make Hive a success!' that they don't actually use it themselves? If the community is interesting enough then people will join, if it isn't interesting, the people won't join. Simple really. Continued speculation on the future of Hive or the value of Hive becomes very boring very quickly.
No amount of 'shouting from the roof tops' will change that. We need to focus on our community, make it interesting and exciting and useful and appealing, and new members will follow.
I just try to do what is fun for me, but it can turn into a chore if you are not careful. Everyone is different and some will be more desperate for rewards than to be sociable. I have been pushing Steem/Hive for years and it can be a hard sell. I think many people are happy enough with FB etc. They do not want to start somewhere new from scratch. This is why I think we need to somehow get more good content creators on board as they will make Hive a more attractive destination. It may just take a few key people for it to go viral. I am happy with what I have here, but how many others will keep waiting for 'moon'?