There is a lot of generalization in this thread. Most of us have very limited experience that's only applicable to a small region, and likely doesn't apply everywhere.
In general, not only in the software industry, people just like younger people more. They're better looking, and they have more energy and enthusiasm. It's a cognitive bias that isn't unlike racism and sexism, it's going to weight the odds in the favour of young people in every industry.
And that's setting aside the fact that older people are closer to retirement and unlikely to spend a long time at the company in question.
In general, not only in the software industry, people just like younger people more. They're better looking, and they have more energy and enthusiasm. It's a cognitive bias that isn't unlike racism and sexism, it's going to weight the odds in the favour of young people in every industry.
And that's setting aside the fact that older people are closer to retirement and unlikely to spend a long time at the company in question.