In my twenty years plus as a screenwriter, I've heard thousands of pitches at pitch festivals, my seminars and in my writing classes.
I'd say that 90% of the screenplays, treatments and ideas I've had pitched to me had a weak premise and probably won't sell. And a weak premise, even well executed, is still weak at its core. On the other hand, a strong, unique premise that is poorly executed can always be improved upon. Studios and production companies have paid sizable sums of money to acquire a slam-dunk premise which they will then hire a seasoned writer to rewrite.
At the present time, the studios are trending toward sequels, remakes, and making films based on novels and comic books. Their thinking is that if you create something with a built-in following that already has some recognition, its chance for success increases. The steady studio box-office decline over the past few years suggests otherwise. This is an industry that is bankrupt for original material.
The High Concept approach begins with a compelling, original premise that has wide audience appeal. It targets the needs of the marketplace because it is contained within the genres that are the easiest to sell. High Concept projects are easier to pitch because they can be communicated in a couple of sentences. It is also easier to get meetings and companies to read your material based on a high concept pitch because they understand what your story is about without a lot of explanation on your part. And if your pitch is strong enough, most producers and executives will be able to picture what the movie poster will look like just based on your one to two sentence logline.
These are some of the reasons why High Concept projects sell for more money than non-High Concept projects and why the High Concept approach can cut years off a Film and TV writer's selling time.