Was it their band name that killed them off in terms of popularity?

[urbanite]

They were never killed off in terms of popularity.  It dipped for a few years, but it came soaring back.  The Beach Boys connect with people in a way very few bands ever have, which is why there is so much attention and excitement being shown towards a group of guys about to turn 70, that haven't released a new records in ages.

[Disney Boy (1985)]

With the exception of Dennis, the Beach Boys WEREN'T cool guys... but hey, that's why i love (and that's why i find the Stones, who just try so, SO hard to be relentlessly bad-ass, a little tiring...)
The funny thing is, in terms of behaviour, the BB's were actually properly MORE genuinely rock and roll than many other acts/groups who tried so hard to create a rebellious image: who did more drugs than/was as 'crazy' as Brian? (Remember how much he scared the hell outta no less than Iggy Pop...) Who had sex more than Dennis, or drank and partied more than him? You want a dark side? This is group who had a Charles Manson song on one of their albums?
But imagine is everything and they were called the Beach Boys and, believe it or not, I still know people who to this day simply laugh the band off, and the group name plays a big part in it: 'Ha ha, the BEACH BOYS? Yeah, no thanks grandad'. Of course these people are complete and utter idiots, but that's by the by...

(Funny however that the Beastie Boys have never suffered the same problem despite having very much stopped being boys several decades ago....)

[Lonely Summer]

At least the Beach Boys TRIED to perform their new music on stage - something which can't be said for the Fabs.

[Disney Boy (1985)]

At least the Beach Boys TRIED to perform their new music on stage - something which can't be said for the Fabs.

VERY good point. And they often did it very successfully - see numerous killer live 70s shows.

[runnersdialzero]

At least the Beach Boys TRIED to perform their new music on stage - something which can't be said for the Fabs.

Whaddya mean "TRIED"? They fuckin' nailed those songs.

[runnersdialzero]

They're ALL dorky dudes, with the exception of Dennis!

I don't remember where I read/saw this, but some interviewee once argued that, unlike the Beatles or the Stones, you couldn't really imagine any of the Beach Boys doing it...except for Dennis.

I don't want to think about anyone in the Rolling Stones or the Beatles doing it sans maybe Paul McCartney. Ever. I'm talking about in their physical prime as well as today. Mick Jagger, no matter the facial expression, always looks like he's taking a sh*t. John Lennon basically always looked like he smelled terrible or at least reeked of weed. Can't/don't want to picture any of these people having sex, and the same goes for the Beach Boys sans, yes, Dennis, but I think having heard Dennis have sex may be a large contributing factor in that.

*in b4 jokes about the dead members doing it today, you sick f*ck*

I will grant you, however, that of all people in all those bands, Al especially conjures up images of... well, a giggly, pokey kind of sex. No offense to Al, i luv u bb.