I wonder if the framing of this feeling you're experiencing is helping you understand your thoughts. A brief survey of your past comments and posts seem to exhibit one common trait, which is to solicit a response from others. For example, your submissions to HN are nearly all targeted to "Ask HN". Additionally, your questions and answers indicate that you make a lot of room for how others around you think, even if it's unclear whether you will follow-through or even listen to what others have to say to you.
Having made this observation, perhaps you or others can jump into the discussion at this point. I don't want to make assumptions since I don't know you, yet it feels incomplete to respond this far without providing a conclusion to my reply. When I see your pattern of thinking, I can't help but wonder if it's possible to take your questions at face value. My gut feeling tells me that you are co-dependent. Your posts are less about the topic at hand but more about engaging with others. Perhaps the first thing to confront is how your identity is so tied up with others.
Now that I've laid out some context, I can answer your question. No, I don't believe that there exists a tension between personal interest and relevance. It's not a rhetorical question to ask yourself how much you love or enjoy something. Many readers of HN can relate to loving or enjoying coding so much, they'd do it in spite of hardship, perhaps even for free. "Soldiering on" with something implies that you don't really want to do this thing at all. Circling back to the paragraphs above, it seems that what you actually love is the engagement you get from others.
Take for example, this idea you proposed of a public square on the internet. What about this do you find compelling? If you were truly drawn to the idea of a public square, you would love it even if you were drawn and quartered on the premise, figuratively speaking.
I anticipate running into more such questions in the future. It takes a lot of work to change. If you keep doing the same thing over and over again while expecting different results, you might find that you've run out of rope sooner than you expect. Good luck!