I've written SDKs that were still in use, 25 years later, on highly modern equipment (digicam SDK -originally designed for film scanners).

The biggest extracurricular project that I did, was first released in early 2009, and is still picking up traction, this very day...

Depends on what you want. Some stuff should not be designed for the long haul, but some, definitely should.

But has that improved your hireability or???

I don’t care.

Just reading some of these comments, makes me happy I have made the choices that I have made.

I don't know that your experience is but I've worked on many products that are 10+ years old. Additionally, I'd take 3 old time engineers over 6 new engineers in a heartbeat. The problem is that every business wants to cut labor cost because that's the MBA way to do things. Why pay USA wages to someone with 15+ years of experience when you can hire three new beginners in the USA or an entire team in another country (again with less experience) for the same amount? The part you're missing from your analogy is the speed and quality of the bridge to be built. Want it done fast and right? Hire the engineers with experience. Want it done fast and possibly going to collapse and end in a lawsuit in 5 years? Hire those idiots.

My experience, is that they are paying kids right out of college, more than I ever made in my career.

They are willing to pay to avoid old.

I would agree with this. Late 40s here, and my comp today is higher than it's ever been, but Im pretty sure my comp as a percentage relative to my peers is at its lowest point ever and will get lower in future jobs.

It is not the case.

The underlying reason is that young fresh grads are running circles around old timers.

I hate to say this, but in quite a lot of circumstances, ageism is very well justified for these reasons:

1. IT/CompSci is constantly changing and high growth area, any engineer worth his/her salt will grow rapidly.

2. High performance old-timers have either retired (earning their $$$) or moved up the ladder to manager/director/VP/Founder levels.

3. Regular IC old-timers who have not progressed in their career - companies don't want them, because old-timer who has not grown in his level - is a red flag for companies.

4. There are some old-timers who prefer part-time/consulting type gigs, but I put them in Founder category, all of them have their own LLC/S-corp and run one man consulting/entrepreneurship shop

This is true.

Everyone knows that old dudes can’t code.

It's funny when people generalize this way. You cherry picked specific scenarios as if that suddenly supports your claim that ageism is well justified. Anecdotally, I've worked with engineers across age ranges. Sure, there are the "rest on their laurels" types who stagnate in their careers. But there are also battle hardened veterans who can debug issues that are mind bendingly difficult to unravel and are happy to stay as IC. I'm curious what metric you'd pick to validate the claim that "...young fresh grads are running circles around old timers." Because based on the quality of the code and other observable aspects this isn't the case. Google introduced a whole new programming language (Go) because fresh grads weren't running circles around anyone and it was easier to go that route than get them to parity with the industry veterans.