I definitely think there is more variety here than the surface lets on. Someone who actually reads romance and bl will soon realize that very few comics are purely that. Because even the people with the highest interest in romance would get bored if lovey dovey tales were all there was to a comic. Usually the genres will be combined with others. Oftentimes it is paired with comedy, seemingly the most popular combo since it is upbeat, relatable and just generally satisfies two major needs that people have emotionally and socially.
But of course there are more combos. Horror and romance is quite a popular combo on Tapas, since they are also the two most popular genres separately. It may not feel like horror is very popular if you take a surface look at the site, but if you are more familiar with the trends and the most popular creators, you start to see it more. Darkbox for one is a prime example of a pure horror creator with longtime popularity. The snipster is one of tapas' most popular creators and she has one foot in the land of horror (she had a series dedicated to horror illustrations and the like, has made horror side projects, and you can very clearly see the influence horror has had on her art and writing even in her biggest comic. A comic many people look at and think "BL"). If I may make an example of myself as well (yeah cocky I know but I am on the first page of popular creators so I do matter statistically in this regard) I also started out doing horror long before I did BL, and most of my projects meddle with horror or darker themes in some way.
This diversity is something that someone without an interest in the genres often overlooks and is one of the many reasons why someone doing a genre they hate is often bound to fail doing it. At least compared to their peers. My advice to creators doing other genres would be to keep doing what you love, post on multiple platforms and consider attempting to approach publishing deals with companies that are more down your alley. Don't make content in a genre you hate just to get noticed; as a creator you are a brand. If you make a lot of BL, you brand yourself as someone people expect BL from. Trying to pull it as a publicity stunt only to ditch it as soon as you have the numbers you want will immediately lose you your numbers since it leaves the audience disappointed. Of course you can get your audience interested in more genres if you wanna do very different projects, but you will have to approach something like that with patience, and the thing that would attract your audience to those new projects would be your art and writing. Which would require passion. So don't write genres you don't like!!!!