In a way, I understand how you feel. After being on so many different writing websites, I've found that most of them are the same, especially ones run by companies. In many ways, Tapas and Wattpad are like the same website to me aside from a few differences. Then again, like others have said, businesses will cater to their moneymakers (readers), so they will promote the content they feel will bring in the funds.
After a while, you just come to expect it. And honestly, I believe romance stories are the most popular ones online (I believe, but I may be wrong). Wattpad, Radish, Amazon, and Fictionpress have a huge romance readership, so it doesn't surprise me that Tapas is the same.
I do agree there should be more genre-centric contests, and maybe one day, the staff here will do that. Until then, all we can do is write our stories and find the readers who will enjoy our work.
I generally avoid writing contests that feel like a popularity contest, so I'm interested to see who the Tapas staff pick as the winners of this contest.