I'd agree that many in the public eye - writers, spokespersons, commentators, etc., whose focus is the gay community - are doubtless leery about opposing such efforts, simply because they fear a backlash from those who see no difference between intolerance of gay folks and opposition to childhood transitioning. (Bill Maher and Jon Stewart, once hailed as champions of acceptance and toleration of alternative sexual identities and preferences are now pariahs to those same people; someone whose sole means of support is to be liked and trusted by the gay community have even more reason to fear a backlash.)
On the other hand, I doubt that the level of support for early transitioning among the general gay population is very much if any higher than it is among the population in general. If they are quieter about it than certain others, it is no doubt because many of the same individuals and groups who are most loudly and publicly vocal about their opposition to childhood transitioning also continue to inveigh against same-sex marriage and gay PDAs on television; it isn't the easiest thing in the world to publicly align oneself with people who yesterday were calling you names and accusing you of being mentally ill, however worthy the cause.