There's no "should" to this sort of thing, but my advice would be -- make the thing you want to make! For one thing, what's the point of making something you don't want to make? What's great about being known for something that's not the thing you REALLY want to be making? It's like pretending to be someone you're not -- if people love that person, you still feel like they don't really love you.
For another thing, if your heart's not in it, audiences can tell. People connect with genuineness, and it's going to be harder to do well with a comic you aren't passionate about. I like the way Gigi D.G. worded it: "Make your comic fun for you, or it won't be fun for anyone else."
THAT SAID, if you ALSO like the idea of doing a funny or romantic stories, or want to try it as a fun personal challenge, I don't think that's bad! My first webcomic was an autobio comic -- wayyyyy outside my normal comfort zone -- but it turned out that I really enjoyed making it, which is why I kept it going for years! But... if you do end up trying something more mainstream because it might be fun, you have to be okay with the fact that this audience might not carry over to future stories you make, and you can't let that get you down.
My current comic is super weird, and that probably makes gaining an audience a little slower for me. But I honestly wouldn't change the things that make it weird, because those are things I love about it. The people who love my comic are invested and supportive and generous -- if you make the thing you love, you'll be able to find the other people who love those things just as much!
P.S. - it might be worth noting that the huge leaning towards comedy and romance is kinda specific to Tapastic. Tapas' format encourages those sorts of comics, so they tend to succeed here. I don't know that the same bias exists as strongly on the wider web.
