I'm sorry but the standards are not that difficult. I'm not saying an idiot can do it or that you don't need basic aptitude but the PTS is a minimum standard and being able to meet the PTS doesn't mean you are skilled, it only means you've managed to meet the minimum standard. There is no grading system, only pass or fail, there is nothing in between. You've either met the minimum standard or you haven't. If you haven't met the minimum standard you can keep trying until you do.
Passing your basic flight training even through ATP is not that difficult compared to the challenges that only experience can help you overcome. Pretty much anyone can pass the FAA written exams, they're a joke. In fact there's no excuse for getting more than a couple wrong answers. Why do so many american pilots fail the foreign written exams or barely pass? Other countries don't have a freedom of information act and the tests are kept secret and change frequently.
Some low time pilots excel and are genuinely skilled and talented, others just scrape by. There is no way to tell except to fly and work with them. If we had a more thorough and objective evaluation system it would be easier to weed out those who are weak and keep them from flying in the left seat of a regional jet or large turboprop before they're ready. All we have now is knee jerk reactions to accidents such as the 1500 hour rule and the pilot records improvement act that usually tells you nothing.
Bad pilots cost the airlines money. It's just that the non pilot bean counters who run the airlines can't really see how. If the airlines hand selected high quality college graduates based on their grades, leadership skills, and determination they could easily evaluate the potential for flight skills and then invest in their training with a long term commitment in return. I think we are heading in this direction but again... The things that are holding us back is this perceived separation of regional and mainline flying and seniority systems.