Board Thread:Speculation House/@comment-4830106-20140806180925/@comment-6863431-20140814075929

Possibly because of the lack of male characters so far (although that number is quickly and drastically changing). Also, a comedic element steps in when you have a guy trying to hit on a lesbian. the play No Exit is a perfect example of this.

But it's still most likely the fact that we are only recently getting a larger cast of male characters. Also, the most famous ships are either (somewhat) hinted at during the series, such as White Knight or Arse (depends on how you look at it for Arse) or are the already-present partnerships within the teams. Whether this is due to the characters' natural chemistry with their partners or because people simply associated the "parter" idea with "possible pairing" depends on who you talk to. But with the introduction of the seemingly all-male team of SSSN, more yaoi ships are bound to launch.