who cares if school of rock was/ wasn't an "autuer" film? he went out to make a rock'n'roll movie with kids in it, and it was good, so who cares if you can't find the "linklater trademarks" in there?
and in before sunset, the two actors wrote big chunks of that screenplay, Julie Delpy wrote the last song, and they were all confined by a grueling 14-day shooting schedule, but that makes Linklater more "autuer" than School of Rock, where he probably had more budget to do what he wanted?
didn't truffaut admit that the whole autuer theory was just a gimmick anyways?
They're just making observations.
School of Rock isn't a typical Linklater film and it isn't the work of an auteur. It doesn't mean it isn't good, nor does it mean that because that complaint is made (and it's valid) that it's a bad or lesser film... well, I guess it depends how much of a Linklater fan you are and what your preferences are like. I know some people that were appalled by how mainstream it was but many enjoyed it for what it is, decent and entertainig which is exactly how soxiante described it.
I don't understand why you mention that a lot of the writing for
Before Sunset was by the actors in your argument against auteurism. Linklater was still involved in the writing and he directed them in such a way to fit his style, his preferences, his way of making films. It just so happens that he likes naturalism and in order to achieve that he gives his actors a lot of freedom. But his personality is still there in every frame, which I think is what the French New Wave and Cahiers du Cinema were getting at. An autuer isn't necessarily in charge of every little aspect on a literal level, but in directing their films their personalities come through and it is undoubtedly theirs. Just because they weren't completely responsible for all ideas or writing involved in the production doesn't mean a director isn't an auteur; that quality lies in their ability to translate all those things to the screen their own way. Wes Anderson doesn't write on his own and he's always asking for other people's opinions, yet through all three of his films you see similatiries in style and personality that are so distinct that it's unmistakably a Wes Anderson picture (I only use him as an example since apparently, you're his bitch). Whether you're a fan of his or not, you can recognize it, and this can be said about a lot of directors; my two favorite examples are Bresson and Ozu, since they're so consistent. But look at the films of Hitchcock and Hawks, Wilder and Sturges, etc. etc.
I know what I described is more or less "personal" filmmaking, but the makers of those films are without a doubt auteurs. Truffaut was announcing his collaboration with Spielberg when he said the auteur theory was a gimmick, which it might have been, but it works, and I like it.
By the way just because Linklater has more budget doesn't mean he has more freedom to do what he wants. Money = liability on the studio's part; that puts him in a more compromising position to deliver something more accessible than what he's used to making, especially since it's a kid's movie (in theory). If he really had his way and didn't consider his audience and adapt to those needs and quotas, I'm sure we'd see Jack Black having existential conversations with Summer while driving the van through, all shot in one five minute take.