It's about the funding and size of GPU clusters. Imagine trying to make practical programming advances with pen and paper compared to someone who has access to

It's about the funding and size of GPU clusters. Imagine trying to make practical programming advances with pen and paper compared to someone who has access to a PC. Sure you can do some theoretical computer science with pen and paper, but it's not the same as practical programming. The difference is analogous to having only a PC vs. having access to a 10K cluster of cutting edge GPGPUs.