It is not a sales pitch.
Although there are less expensive alternatives, the Orvis schools can be a good option. I took one (Evergreen, CO at the Blue Quill Angler in 1998) with my wife; it was for her. I could fly fish, but at that time I could not teach another person - I have recently taught my son and several others. She had fished before with a guide, but the school improved her technique and understanding. The school covers everything from aquatic insects, types of flies, rigging and casting. It is a good balance between classroom and outside practice/fishing.
If you are starting from zero, it is a good place to start. Even if you have fished for years (spin), you are essentially at zero for fly fishing. I believe that everyone enjoyed the school, and many caught their fish ever. Reading a book before you go will help you learn faster. They did not pressure anyone to buy anything; I think most people plan to buy their equipment if they enjoy the school.
BTW, my wife and I spent 3 days/2 nights on the Green River below Flaming Gorge dam the next week. She had a great time and caught as many fish as I did (we both caught a lot of big fish). We have fished for a day or two on most vacations since the school, and she still enjoys it.