Joyce, I think not only the language industry but pretty much every industry out there that markets to the public.
Por ejemplo, tu comentario ""thin thighs in 30 days"...¡qué chistozo!
We citizens of the United States...and maybe other places as well...have been conditioned to think that anything and everything can be had quickly, easily and with little effort on our part. All it takes is money.
To answer your question, I think that some people would part with their hard earned money if they knew just how difficult learning a new language is. But many of them would get frustrated and would quit, leaving about the same number of us who will succeed.
What keeps me engaged?
1. I have always wanted to learn a foreign language.
2. I fancy myself a traveler rather than a tourist, and I think that travelers should accommodate themselves to the places they visit, not the other way around.
3. I hope to meet Sofia Vergara some day and talk to her in Spanish.