I agree with both of you. Releasing new ships is absolutely fine and I want to see more of them. What I don't want to see is 'more of the same' that is slight variations because that becomes old pretty quick and meta ships reduce varieties.
I like Coolgrove's idea to create new ships along new game loops. Yes, probably even more development work but that could justify an ongoing revenue stream and in parallel more fun for the players.
I am thinking of unique ships which can carry oversized SRVs for planetary transport (ok, that would be a lot to develop but huge fun

), racing ships, construction ships for the colonies which have unique modules (e.g. air tanks, cranes, etc.), exploration ships for high-g landings. I admit, I am not a game designer and therefore lack creativity but I hope you get my idea