I think every 50 year old is different. A fifty year old who did some regular exercise, is different than a guy who spent the last thirty years sitting at a desk?
When I was younger, I thought most people over 30 were basically worthless. As I've aged, I changed that up a bit.
Young and old have their place.
When I was in my twenties, and thirties; you couldn't pay me to sit in front of a computer--literally.
What was I interested in? Guess? Girls! And then Girls! And then anything other than sitting at a desk all day, especially looking into a screen. Was I entitled? A bit?
Only as I aged, did computer science become palatable. Do I love it? No, but I haven't loved anything besides a few family members, and my pets.
I think where Hiring Managers get it wrong is assuming all young people will be Rock Stars, with great ideas. They will be happy with free food, and lofty promises. I never bought it. I took what I wanted. I smiled, looked promising, but hated my employers. I would not want to hire myself after college. I finished college ready for med school, and looked back, and could count on my hands what courses weren't a waste of time. I was dissalusioned.
I do think the best ideas still come from mainly young people, but separating the the best from the herd is impossible.
Peter Thiel has the money to throw at young people, and wait for the shooting star. He knows that combination of being young, hormones at full throttle, and angst; might just produce another Mark Zuckerburg. (I used Mark, but he might have just stole an idea, and got very lucky? I honestly haven't figured it out.)
And to be perfectly honest; the young guys, I know, who became rich--all had wealthy enabling fathers. The more I think about it, it was their fathers(50 plus) who provided the idea, and capital, but weren't willing to give up their day gig to see their product through.
The ageism won't go away soon.
I think it will take another five to ten years for the industry to realize you don't need to fire programmer at 40, but who knows?
I personally think in a decade, this profession will be talked about in the past tense. Yes, a few will always have a secure job, but most jobs will be contracted out to the lowest bidder.
Hell, I don't think it will be ten years. Once "Let it go whatever", rehashedidea.com, etc. run out of free money; we will have a huge group of dissalusioned 25-35 year olds. Many will be homeless? Many talking about the good ole days when companies treated you like you were a valuable commodity.
"Rember the free stuff?"