It's interesting coming here and seeing the different perspective that pure CDers seem to have, when I'm so used to primarily TS dominated communities. On a personal note, while I agree that MtFs are more prevalent on the internet (or at least make themselves more visible), in real life, I only seem to come across FtMs. But either way, it's hard to know real numbers, especially when (at least in the full on TS category) the most successful may never tell anyone about their situation. So all you can really ask is "Why do I see so many more MtFs than FtMs?" And maybe it's just a matter of difficulty. Testosterone is strong, and hiding its effects is quite a feat. Perhaps I'm biased, but I'd guess it's just harder for us MtFs, so we're more prone to seek out each others' help.
EDIT~Ack. You beat me to it while I was typing. :P