No, it IS because there were jobs that experienced pilots would not take. There are PLENTY of experienced pilots on the streets. They had to drop standards to 250 & 50 to keep fresh meet in the right seats. They could not lower the minimums any lower than that, and they still couldn't get people fast enough. Was it because that many people were retiring? No, it was because that many people worked for a year or so, and realized how much they were getting screwed and left. The vacancies were all due to turnover rates for the most part.

That still doesn't change the fact that there were/are plenty of qualified airline pilots that have decided to make use of their College education in their other field of study since the money is better, the hours are better, and the QOL is better. If the money and QOL were still here, they would be too.