Non-hetero-normative sexualities and lifestyles (or even viewing sexualities as anything but binaries) is a hot-button issue at the minute. Games are meant to make money and publishers usually assume that public reaction towards positive portrayals of potentially controversial topics will be entirely negative, and thus bad for sales (never mind that there may be a very large group of people who actually want that sort of thing in their games). Developers with more experience, franchises under their belt, etc. have far more clout as well, especially if they are able to self-publish, but still have to be careful. Inserting discussion of sexuality into a game where it isn't necessarily warranted isn't really going to help anyone, and going about it in the wrong way, even in the right context, can lead to other problems such as ornamentalising.