ADS-B is definitely more popular than AIS, and I've always wondered why. Perhaps it's that airplanes evoke more wonder, and is more accessible over land than poor old ships?
Do DM me if you're looking for a position, or if you'd just like to chat about vessels, AIS and anything maritime.
We're building maritime intelligence at Greywing (https://grey-wing.com), and I'd love your input. In fact we have a Launch HN post up right now, so if you have any thoughts do drop them in!