Or, I guess maybe I just couldn't think up a better name for my theory, but now it's too late to change it. So I'm stuck with it. Shut up and deal.
The Free Film Theory goes like this: a writer's critique of a film is based not merely on the writer's impression of the movie, but on the writer's past critique of the director/writer/actors involved in the film in inverse relation to the general popularity of those films.

Let me explain.

Suppose that one of the summer's big blockbusters is a unexciting messy windbag clunker of a film (if your imaginations are that good). The critic who sees this movie loathes it on sight, and reviews the movie accordingly. But where they place the blame for this failure is based not on whether the direction was awkward, or if the acting choppy and wooden, or the special effects garish and unconvincing. The blame is placed on the person they most feel should bear a little more blame, shielding the people the critics find deserving. How do they decide which is which? Funny you should ask. These decisions are decided mostly by the box-office results of the movies that critics either panned or praised the last time these actors/directors/writers were around. Really.

I'm sure you're doubting me, but keep reading and I'll give you an idea of how all this works.