Because they're both threats to their power. If Ma had gone public, he could have used the foreign money in the way that Whitey Bulger used the FBI to eliminate his rivals within his own organization and then in other gangs. It's the double agent game most spooks excel at, so the CCP saw it coming nipped it in the bud. (It's also why I think Ma's been dead for quite some time. A country with billion smartphones and not one picture from some random waitress? C'mon.)
The CCP are is obsessed with the relationship between demographics and war because it always thought that their extraordinary numbers would be their saving grace in WWIII. Now, for a lot of reasons, they're really not so certain.
If you're a CCP leader, gay men aren't the problem so much as it is lesbians. (I've never seen trans people enter into the debate at the policy level, even though all three are existential threats to Confucianism.) The gender imbalance caused by the one son policy really is a problem because it means you have tens of millions of unmarriageable single young men. Historically, the more unmarriageable single young men you have as a percentage of your total population, the more violent crime your society has. If you hit a certain point, revolutions become far more likely. Lesbians -- as well as Chinese women who prefer Western men, their careers, or anything else -- have to be stomped out by any means necessary because because they feel that they are uncomfortably close to that tipping point. It's why a lot of people think the campaign to denigrate leftover women ultimately came from the CCP.
Interestingly, its this demographic imbalance that is the reason for gay porn to still be somewhat tolerated, even if forums aren't. (Lesbian porn still isn't.) Chatrooms and forums are bad because they encourage solidarity and planning; porn is okay because you're just sitting in a room staring at a screen.
Edit: Am I the only one who's a little disturbed at how closely the English language media has followed the Chinese language media on this? And people wonder why I stopped using FB/Twitter/smartphones.