Unfortunately it's not limited to slash. I've seen this kind of thing when it's male/male friendship fic in many fandoms. I've got this genfic rec. LJ comm. on my viewing list and most of the time I'm afraid to read the fic if it's shep, mckay.

I'm tempted to ask the authors how they weir in each fic I come across that isn't Shep/Weir.

It's sad how most S/W shippers I've come across respect the relationship John and Elizabeth have with Rodney while many of the Sheppard/Mckay fans don't respect the relationship John and Rodney have with Elizabeth.

I guess I'll just have to write my own fic.