In creating a new campaign, I find that a lot of genres simply don't appeal to me enough for me to do the work to run them. For some others I have troubles making a campaign that is actually game-able, as opposed to predestined story action withe players strapped into character bodies and obliged to read a fixed script. (I made that mistake back around the turn of this century, and I've taken great pains to avoid doing it again.)
Really don't like horror. Not keen on superheroes. In general, I am not interested in most intellectual properties (e.g., it takes intense peer pressure for me to participate in a Star Wars game). We have a large group (usually five players, sometimes six, plus the GM du jour), and I have a difficult time making a modern spy campaign work with that big a group. You might think I'd be able to run a space sci-fi campaign, but no, I know too much real astrophysics and way too many genre tropes there clash violently with what I know. Fantasy is my go-to, and I can work with different power levels for the magic part, but most of what I've actually run has been Western-style high fantasy.
Genres not already named ... I may be able to work with if I am allowed slapstick.
Only after I've decided whether I can enjoy running a game with a particular concept do I address the question of whether the players in the group would be interested in playing it. Of the group of five plus myself plus one part-timer, all but the part-timer have been running RPGs for decades (I first started running back in 1975, e.g.).
Now, I haven't run anything for about five years now, but I am getting the hankerin' now that I've got time. So I am working up a concept (and making sure I can pull it off) now but I haven't floated it in the group yet.