It even seems to provide proof that being an older IC makes you irrelevant because the success story is not a coder. The lesson is that as you age it's either up or out. You either learn higher level skills or slowly fade into irrelevance as your ideological baggage acts as an achor distancing you from keeping pace with the now constant supply of young grads. (Now that coding is "cool")
At the very very abstract level, companies are divided into people seeking meaning and those that provide it. Upper level executives provide meaning in work for the ICs. For the middle level executives they provide meaning in the "company".
As you age, you're expected to be more wise and knowledgeable. Staying as an IC is a black mark of sorts that you've plateaued at some point. You either need to move into a meaning providing (or meaning enforcing) role, or stay as an IC but provide meaning in the form of technical wisdom. Otherwise, all else being equal, you stand out amongst the younger workforce.
Previous rewarding specialization does not mean future rewarding specialization. The world can shift in a way so that your skills and ideologies and perspectives are useless. The ageism prevalent in silicon valley is that it's unkind to equally skilled low level people with one lerson being older.
If your an older person and your skills are actually in great demand but low suppl(strategy and meaning making)y, the ageism doesn't apply.