Parents of boomerang children are getting exactly what they deserve for raising children who are lazy, spoiled, dependent and who feel entitled to a lifestyle they cannot provide for themselves. These parents are "paying for it"--literally.
Years ago, I met a successful couple who had worked their way to an upper-middle-class lifestyle. They had worked for years to have a big house, nice cars, exotic vacations, etc. When I first met them, they were in their 50's and still worked full-time.
They have a daughter, and they paid for Daughter's college and graduate education. They also give Daughter extra money for "living expenses" (designer clothes, first-class airfare, BMW and other things that she could not afford on her own) on a regular basis. Perhaps they expected that Daughter would eventually work her way to financial success, be able to support herself and not need their financial assistance anymore? HA! Daughter is now in her early 40's and is still a financial black-hole for her parents. She chooses to work part-time jobs or lower paying jobs that are fulfilling to her. Her parents still subsidize her so that she can live the lifestyle that they live. They seem to want her to appear to be successful, so they continue to give her money. Maybe they would be embarrassed if their friends knew the truth: Daughter is a well-educated parasite?
The husband is now retired, and the wife is very near retirement age. They have little saved for retirement (perhaps because all the extra money went to Daughter instead of into a retirement fund?). They told me that they expect Daughter to take care of them when they are old, because they have done so much for her. I doubt it.