It's undeniable that The Master is about Scientology, specifically Hubbard's early years, but it's perfectly understandable why Paul Thomas Anderson doesn't want to talk about it.
I think if you look at There Will Be Blood you get a sense that PTA is a director who takes himself very seriously, and you can view TWBB as a sort of historical fiction where its power derives less from the source material than PTA's impressionistic take on the story. I think he'd feel that he would be undermining what he sees as the essence of the film if he were to admit what it is "about." It wouldn't only cheapen the film to call it a biopic, but if you label it as such you also shorten your license to fictionalize, because then you're forced into a discussion over what was fact and fiction, questions he's smart enough not to want to answer.
Hubbard's early 1950s, and the company he kept, is really interesting, untapped source material for filmmakers. But it's also contentious, at least between Scientology's pure fantasy version and Russell Miller's far more plausible version told in "Bare Faced Messiah" (which based on what I've seen and heard so far, was likely PTA's key source). In other words, PTA is not only smart enough to know that any discussion of Scientology will detract from his film, but also because that discussion places him in the center of a never-ending argument.
I suspect he'll be more willing to talk about Scientology and Hubbard a few years from now. But in the promotional phase of a movie, which I imagine is the least fun thing a director ever has to do, he wants to do whatever he can to keep the focus on the movie, and talking about Scientology achieves the opposite.
Stop Asking if Paul Thomas Anderson’s New Movie Is About Scientology, Even Though It Probably Is
If you’re a fan of Paul Thomas Anderson films — Boogie Nights, There Will Be Blood — chances are you’re excited about The Master, which has already been hyped to death by festival audiences. But what …