I don't think you really do if you are just responding to comments with useful info. You might if you want to make top level submissions. But I don't think anyone has an issue with for example, Gitlab people commenting officially answering questions on Gitlab. Their contributions on other threads is irrelevant.

I don’t think people have a problem with that, but it’s not the same thing as what the OP was talking about.

You aren’t living alongside your customers by popping in and answering questions about your product when you get an alert that someone mentioned it on HN.

And that feels like the problem. You can't live alongside your customers unless you are truly invested in the community, and it feels rare that passion for the community would be weighed higher over the sales position salary when job applicants apply to a position.

It really comes down to the sales hiring manager recognizing this passion/emotional investment in applicants and weighting it properly. And also having a pool of people with this passion who want to work sales at this employer to begin with! How often would this actually happen in practice?