They could be worth it. If 1 in 10 of those voters directly becomes a customer (or mentions it to someone else who does), and the LTV of a customer is > $1k (which is very possible for a b2b relationship), then it is. And that doesn't factor in any customers (or investors) bought in by having greater visibility on the post (more votes = more time on front page = more people see it = probably a few more customers).
This is important how? Are these ~150 extra up votes really worth $100 each? Really worth 7.5% of your funding round. Yeah, yeah, yeah, visibility on HN is good but outside the HN bubble I think I'd rather have the 15k.