For the profession as a whole, that's probably true, but 100 individual self-interested decisions have not yielded a good result for the group of 100.
Who will volunteer to give up his chance at prosperity in order that the others may have a better chance? This much-discussed philosophical problem is often referred to as the "tragedy of the commons":
Imagine that 100 applicants are interviewed separately and each is told: "We'll hire all of you who sign up, but the quality of the job will vary inversely with the number employed. For example, if only 20 sign up, they all get good jobs, but if all 100 join, they all get lousy jobs. The non-refundable signing fee is $100k. What's your decision?"
ALPA founder Dave Behncke thought that the solution was one union encompassing all airline pilots, but it never came about.