Concerning Less Wrong's tagline, consider this plausible reaction of someone looking at LW for the first time:
Cut the crap, nobody cares about rationality in the abstract. Just tell me what view you're trying to push under the guise of presenting it as the only "rational" one.
And here are two real quotes from 2009:
[concerning the ban on SIAI discussion during the first weeks of LW] I think it was so that newcomers wouldn't think that LW are a bunch of fringe technophiles that just want to have their cause associated with rationality.
And in reply:
But that's pretty much what LW is, no? I've long suspected that "rationality," as discussed here, was a bit of a ruse designed to insinuate a (misleading) necessary connection between being rational and supporting transhumanist ideals.
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.
I suspect a lot of people do, but how strong it is varies. I would take a look before, with an eye out for crankish or biased tendencies. Of course by the time I got here I knew this was legit.
A possible way to defuse this would be to add a second tagline that motivates understanding rationality for the purposes of building it. Then the agenda becomes clearer: yes, it really is rationality, in itself, for a specific purpose.