Supporting Black Engineers with Aston Motes, Dropbox Employee #1

One question for this community related to the discussion: why DON'T you start a startup?

We talk a bit about having enough wealth to feel secure, like you can't lose it all. (17 min in https://www.youtube.com/watch?v=ticjeKVgA7Q&t=1020s )

PG has a whole post on this: http://www.paulgraham.com/notnot.html

What is your reason?