I think "myth" means "a lie" here, because form the whole article, I can know that "mobile phones can cause explosions at petrol stations" is not truth. Then what does "no less" and "for that" mean? Are they fixed phrases?
(context: Do mobile phones cause explosions at petrol stations? That question has just been exhaustively answered by Adam Burgess, a researcher at the University of Kent, in England. Oddly, however, Dr. Burgess is not a physicist, but a sociologist. For the concern rests not on scientific evidence of any danger, but is instead the result of sociological factors: it is an urban myth, supported and propagated by official sources, but no less a myth for that. Dr Burgess presented his findings this week at the annual conference of the British Sociological Association.
from
Anatomy of a techno-myth)