You say it like it's the truth. "There is overt discrimination against people over 40."
Discrimination is one thing, pragmatism is another. Young people accept lower pay, and possibly perform the same job as well. Of course companies do not want to hire people over 40 who might have been problematic (since they are jobless over the age of 40). You gotta see it from their shoes, thankyew.
Read what you just wrote, your statement stinks of small minded discrimination.
You are right, companies do fire people over 40 so that they can be replaced by young people whom they can pay a pittance. But they don't realise the intangible cost - the lost of experience and knowledge..
There have been a few news articles not only in the local media but international too regarding this problem.
It is not true that every person over 40 is problematic. If this were the case, you should tell your parents that they are problematic people and that their companies should fire them now.