Seems to me you could replace "fringe technophiles" with 'white guys not named Harold,' and have just as valid a statement.
I assume you mean that your description gets at what a random member of the public would likely notice first. This does seem close to the truth. (Although a more literal account of what they'd perceive first would involve some word like 'rationality' or 'reason', perhaps in connection with the term 'worship'.) But the term "fringe technophiles," by itself, would not lead anyone to expect a community that asks you to justify your belief in detail if you say technology will not destroy the world.
Except the agenda of the fraction I'm speaking about is not "technology will not destroy the world". It's "friendly AI and uploads will lead us to a bright perfect techno-utopia". And as I said multiple times before, I don't buy it.
Concerning Less Wrong's tagline, consider this plausible reaction of someone looking at LW for the first time:
And here are two real quotes from 2009:
And in reply:
The quoted text speaks for itself really. So therefore I think LW's admins/web designers should seriously consider replacing the rationality tagline with something more savory.