I suppose part of what makes BiSH so easy to dislike, if you're a BiS fan, is that BiSH are way more "idol" than BiS ever were, in terms of appearance and how they function as a group. If we're holding BiS up to be some sort of alternative idol icon because of how unconventional they were in all things, BiSH can't even hold a candle to what BiS was. However, the music is good, the girls are cute, they're fun to watch, and that's all I really care about.
And while the Watanabe interview implies they were pretty much conceived as a BiS copy act, maybe he had a change of plan, as they're certainly now an act in their own right.
I'm not sure that I'd really disagree with much that's been said in this discussion. I'm generally pretty cynical about concepts such as subversion and authenticity in relation to pop music (I go back a long, long, long way, and I've seen a lot, some of it from far too close), so I guess that my expectations for anything genuinely radical are low. But that's OK with me, as long as what happens is fun, and I like the music, which at this point is generally the case.
I do want to put in at least half a word for Billie Idle -- they actually won me over with the "Anarchy in the Music Scene" PV (in part, I suppose, because there's just enough sacrilege left in something like that for me to appreciate the irony, but I actually do like the song), and I find myself liking several other cuts off their album. But it's hard not to draw a parallel between the BiS spin-off groups and the various Sex Pistols spin-offs, most of which are little more than footnotes in rock history (The Rich Kids, the Ronnie Biggs single, Sid Vicious doing "My Way") -- although I actually liked those quite a lot as well. 
The Rich Kids had a few really good songs which for me are more listenable today than the Pistols, and we no longer have that problem of liking something that Midge Ure was involved with!
The Sex Pistols themselves are actually a good comparison to more controversial and "rebellious" idol groups.Sex Pistols were a punk rock band and they did a lot of controversial stuff but were still very mainstream and the stuff they did was publicity stunts they were not trying to rock the boat but capitalise on a movement and a feeling among a certain crowd. It doesn't make them bad they were very fun but they were not really trying to be anti establishment but they had good management who painted them as rebels starting a revolution.
Of course McLaren stage managed a lot of the things they did, and had more success with his stunts than he could ever have dreamed, but even though they reached No. 1 in the singles charts with "God Save The Queen" at the height of punk they were still never 'mainstream'. Maybe it looked like that from across the pond, but trust me, they weren't.
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