Mortte, the situation you descfribe results from the fact that for years and years, the ONLY band making music that satisfied a specific noiserock mashup primal need was Sonic Youth, and when they stopped doing what they do so well, no one else will come and fill that void.
Like all singular musicians. When Dylan dies there will be no more Dylan. When he switched to electric guitar and rock music the folkies went nuts, some felt betrayed, sure, but most I am certain just felt that, "Oh fuck, now we have no one making the kind of intelligent, dense, folk music that Dylan mastered."
I can understand how people feel that way about bands like SY when they make albums full of sad, rainy day songs, or albums full of poppy, peppy 3 minute rockers...
it is all subjective bias of course, but that is all we have!