I just cannot wrap my head around the co-founder reacting this way in a thread about his company.

I too don't understand what I would use this product for. That doesn't mean it's a bad product, I just don't have a personal need for it.

I don't really like eating grapefruit. If you're a grapefruit farmer, it doesn't mean you farm a bad fruit. Lots of people like grapefruit. I just don't like it personally.

Calling someone like me an "HN troll" because they're critical of your product is a pretty bad look.