Figuring out the right amount of endowment is quite difficult, but you certainly need a LOT to get the outcomes like PARC. Are you running it off interest or burning down the pot? Also possible that we are simply in a different techno-economic and scientific moment than those researchers were (ie it was cheaper for them).

Also once you start framing it as investment or a biz decision in a big public company, the natural question is whether it's the best use of capital for Apple. It's not really about short vs longterm thinking either, it's about the deployment with the highest likelihood to return on any timeframe.