Rich technologists are exactly the type of people who should get PhDs in the humanities, since they require either a) you to have sufficient resources to live a life of leisure or b) external support by an organization which has a pile of rent and a big desire to spend some to signal status. Sell your startup, go get a degree in English. Become a Scholar in Residence at e.g. Google, do some pathbreaking anthropological work about youths' use of mobile devices. Whatever.

If you actually work for a living, though, this is terrible advice.