I knew software development ageism ran rampant over 50+ workers, but IBM seems to have set a new low bar of 40+.
In my view, companies that practice ageism are looking for followers, not leaders. You must have a type A personality to drive yourself into a leadership position; merit isn't considered.
Leadership should be based on merit, and merit can require time to establish; this runs counter to ageism. Leadership also doesn't mean management. i.e., lead by example.