I'm late to the post, so I doubt this will get read, but I'll share.
When I've hired devs in the past (past 15 years or so) the question I ask is "what do you do on your own time?" It used to also be "tell me about your home computer set up" but not anymore. For that second question, if they said they had dial up AOL, fine, interview over. If they said they networked it themselves (before the days of wifi) and had a couple of versions of linux going, in addition to their own domain controller and desktop, then I wanted to hear more.
Back to "what do you do on your own time?" What I want to hear is "I code. I dabble with my own ideas or help out other people online." Or I want to hear about how they are dabbling with some weird new language, or open source project, or framework, or whatever, even if it had nothing to do with the job. What I want is that passion - that obsession that is so strong that they want to spend as many waking minutes as possible trying to figure out creative solutions, solve problems, and make a difference. Then, it's my job to point that in the right direction and make an environment where they can thrive, learn, and stretch themselves. I don't want a 9-5 developer. I don't even want someone that says they are an outdoors guy that hikes every chance they get. Yes, it makes you interesting, but not a great coder.
And that's the issue, not age. Most people get past that single minded obsession. They decide (rightly so) that family is more important, kids are important, that they can and want ot leave work behind at the end of the day. That's wisdom and experience that comes with age. For a line job, I don't want that. I want the guy that will pull an all nighter and be thinking about how to fix something continually until he figures it out, and has no higher priority than writing elegant fucking code. Coding is not a job or a paycheck, its a lifestyle. Now I don't want a sweat shop, I want that person to feel like they are making a difference they can see and are getting rewarded for it, but nevertheless, that's the behavior I want, and I want that person to feel like they've landed their dream job. I know that one superstar alpha-coder can do the work of 10 ordinary ones, and I know how to spot them, and I don't want to settle.
It's a fact of life that generally speaking, with age comes temperance. Not always, but mostly. Are you a 50 year old that can hang with that type of person? Then you'll have a job. If you want to come in and demand fixed hours, and communicate that life outside of work comes first to you, that a job is a paycheck and not a lifestyle for you, then this isn't the best line of work for you. For me it has nothing to do with age. I'm also a veteran and I think women should be allowed in the infantry if they want, but I also think they should meet all the physical requirements of carrying weight, long distance marches, hoisting weapons and the like. I'm fully aware that it will eliminate 99% of all women, but that's not unfair to me. Neither is it unfair that most "older" people aren't cut out to be an alpha coder.