I have disabled my "Share on Facebook" for one simple reason:
Drama.
The stuff that happens around BYOND is sometimes appalling, and I don't want to be linked for something. If it were more of only the Author, of the content on BYOND, had the powers to link to Facebook then I'd me more than happy to put my "Share on Facebook" link back.
Either that or only those I chose that have joined my site to have the power to share it on Facebook.
Spreading the word of and about BYOND is indeed a great way to attract more members, but if they were to see someone posted on the BYOND's Facebook containing a blog post that doesn't appear to be friendly, it might turn them right around because doesn't it also get displayed on BYOND's Facebook as well as your own?
The former is only an issue if you personally identify yourself, actively take part in that drama and also fail to moderate your own blog and comments. BYOND and your common sense has provided you more than enough, such that other technical measures aren't needed.
The latter can be compared to the case where you don't tell the world anything at all anyway. The end result is no growth either way, except that facebook linking has the potential for growth that sitting here doing nothing lacks.
Blogs are public, for public consumption. If you are upset that people might see them, why are you blogging?
Meanwhile, the front page is not a member benefit. People are expected to subscribe to those they wish to follow. The terms of service state that the privilege of being displayed can be taken away if your site is determined to be detrimental to the interests of BYOND.
Instead, the front page is an advertisement aimed at everyone else. It's the text equivalent of YouTube's featured videos. Those not willing to let the public see their posts don't understand the point.
...Do I think these bans would actually happen? No. I just think many of the complaints come from self-entitled brats with little idea of how social networks operate.