I've been in programming and IT since I was 18 years old and I've NEVER seen an issue of age discrimination. As an example, the CTO at my current job is in his 60s. I am 34.
A trend I do see is that older people stop caring after a while. I work in the healthcare industry and we get strict audits constantly due to HIPAA regulations. At a previous job, about half our staff was laid off once due to refusing to fix issues that came up during 3 different audits. The majority of these employees were older, 45+. They attempted legal action, but it didn't get anywhere. The things that came up were explained off by responses such as 'it's not a problem' or 'we don't have the resources to fix that'. The company got tired of hearing no and losing clients, and after an investigation via a 3rd party, they fired all of those that refused to do their jobs and brought in newer folks. The newer folks fixed the issues within 2 months and the company doubled in size, revenue, and profit. All of the newer folks were people in their prime years, all getting married, having babies, etc. Most in their 20s and 30s
I came, I saw, I deleted all your files.