The term "gay" is only offensive if used as a perjorative. I kind of think just-in was using it in that sense.
It is kind of like how it is only appropriate to call someone a Dick if that's actually his name. Otherwise, you mean it as an insult, and while there is nothing wrong with insulting the Borg when they have it coming, using "gay" (or even "Dick") ends up insulting an entire group of people that shouldn't even be the object of the derision.