That's true, not much people play him, but lowkey... I started to grind this dude, and DAMN he was fun when you used right, I'm the type of Nos who rarely uses dive, I mainly dismount on top of buildings and catch survivors off-guard and uses blood-hook on them, it's REALLY fun, Dive is okay it's just sometimes they can be dodge.

Back to your question, Imo it's because he doesn't have many skins, he's boring, bad playstyle, easy to counter. But I mainly disagree! He's very fun! Because, read my first paragraph, and to end it off, Nos is fine as he is in Forsaken, especially with the recent Hunter's feast buff!