These are very open ended questions. I wouldn't tap into the genres that I do, if I didn't think there was something interesting to be represented in all of them. I'd say that the fewer elements you can manipulate, the more difficult it is to make a song interesting. So if I'm writing something for only piano, I am limited in that I can only use a piano, but it also means that there are no distractions from the harmony and counterpoint that is being presented.
On the other hand, dance tracks have more elements - ie: bass, kick, percussion, lead, fx, sweeps, and you have to keep in mind structural elements like intros, breaks, buildups. But each of these elements are relatively easy to construct on their own, so there is more focus on putting them together.
Then, there are the miscellaneous pieces that I do, some of which are intentionally experimental, and some of which just don't quite fit into any genre. These are usually fun to make, though sometimes I feel like many of them are misfit pieces that I could have made into something more defined.
The genre I want to write at any given time depends a lot on what I'm in the mood for, as each genre requires different thought processes. Sometimes I just sit down at my piano and mess around for hours not even knowing whether I'll end up creating anything worth posting, and other times I'm motivated to create something electronic with a dance feel that I intend to be "popular", something that will appeal to fans of the genre.
I think it's very important for musicians to be willing to be eclectic, even if they are not consistently so.