Wow. It's like they haven't noticed that there's an Irene Adler in the Sherlock Holmes film. Or noticed that she has been the one and only romance lead we've had for decades, and we love the mystery of it. (Just me? okay then) Or noticed that for all the modernization of Moffat's Sherlock, he's more "canon" than the films. And he's been stealing details left and right from other original stories that are not in the original story they are adapting.

I'm entirely confused as to why it "would ruin season 2"
they have no idea where he's going with it.
Half the fandom slashes Sherlock and John anyway, so any heterosexual relationship is going to be looked down on anyway.