HN users, like most nocoiners are reasonably skeptical of Bitcoin. As they should be. Cryptocurrency is dangerous, and if you don't know what you're doing you can lose a lot of money fast. The upsides of cryptocurrency are very abstract and hard to grasp on an individual level (privacy, security, decentralization, competition, etc). While the downsides of cryptocurrency are obvious, immediate and material (scams, cyber-crime, electricity use, etc); the average joe has "heard enough" about bitcoin from the mainstream news scaring him away.

HN users are way more informed than the average joe. Most of them grasp the basic concepts behind cryptocurrencies. Most of them work in an industry where "blockchain" and "decentralization" are grifty buzzwords, so they are reasonably skeptical about any project that uses these words.

I have had a lot of success shilling monero on HN. You just have to pick and choose your battles. You can't win every argument, but you can briefly make a few good points.

Bitcoiners have largely abandoned the "digital cash" narrative (to their own detriment). If you want to convince people about bitcoin, don't tell them that it will overturn the global economy, don't tell them that it will completely revolutionize society, don't tell them that it's the greatest thing since gold, don't tell them to invest. Just tell them it does one thing and does it well: digital cash. Everything else comes second.