Author probably meant 20 years of experience. That's quite a long time to stay in an industry that values the wet-behind-the-ears-excited-to-be-exploited developer. I've long supposed the "ageism" in the industry is largely people just getting tired of keeping up with the coolest new toy. I've figured that if I lose my job I will probably need to leave the industry because I just can't be bothered to learn the Next Greatest Thing that Google is shilling.

I don’t understand. Somebody who has been developing for 20 years is likely in their late 30s or early 40s at least. Did you read that as the poster claiming they were 20 years old?