Y'know, some of this thread is starting to sound a little stealth shamey.
I think that out trans people are useful to the trans movement in some respects, but not entirely. I for one have serious worries that one day I'm going to be outed by the scars I'll get from top surgery one day, to the point where part of me is leaning towards considering peri even though I generally don't like the look of the outcomes as much. When I'm done with transition I just want to forget about it all, I'm just a regular man, and I want to forget all of this bs we have to go through to be seen as one. There will always be little reminders, but I don't want one of those to be people noticing my scars in public and saying things, because once one person says something I'm going to be forever paranoid that everyone who stares, even if they're just curious because people can't always help looking at big scars, knows my past. And if those scars are publicly broadcast around the place the whole time then it might become a big problem.
My next point sort of contradicts the above one a little, but I've never met an out trans person, and I don't think that a brief encounter with one would educate me, or have been enough for me to realise I was trans, back before I knew the name of it. I'm all for people going on TV for well thought out documentaries, or even well written trans story-lines, because that's how I discovered what my feelings meant, but I don't think that having a bunch of trans people being out would ever touch my life enough to spark up the "that's me" warning light in my brain. I also don't understand the dynamic of how it works to be an out trans person, except for those who don't pass, but if we want to be accepted as "normal people" (by this I mean not the freaks that some cis people view us as) then surely we should be making being trans a minor part of our lives, not some big deal that we have to tell everyone about? That said, I have no interest in ever being out, and I don't understand how some people manage it, or how they go about being out.
One day all trans people will be seen in the same light as cis people, but honestly, I think that's a long time coming. In the 18th century african-american slaves started revolting, and 300 years later the colour of peoples' skin is still something which makes people unequal, despite years of fighting to make it not so. Maybe more relevant, the sixties held the first public protests against homosexual discrimination, and fifty years later most of the - for lack of better terms - western countries are only just coming around to the idea of equality, and there are many who are still homophobic, and potentially in positions of power. In my personal opinion, people just being out isn't enough to change the state of play for trans people in our lifetime, we can't rely to be carried on the backs of the LGB movement, and no one ever got anywhere in history on their own. If people are going to be out in order to progress society, then they need to do more than just be out. It might help their personal social network, but not that of their state, country, or general society. Just to clarify, this is entirely my opinion, and I'm not saying that to be out you need to be fighting tooth and nail for our rights, and nor can only out people fight for our rights, but if that's people's motivations for being out then I don't think it'll achieve very much.
In short, there are both pros and cons to being out, and to being stealth. Without some people being out then there's much less of a chance of trans people understanding that being trans is a thing, but there's the problem that some people could end up being outed due to other trans people being out. Of course that's always going to be a problem, but it could be lesser if the layperson doesn't know our tell-tale scars, etc.