Since the RSUs are a significant (ex: 90%) part of their equity portfolio, it makes a lot of sense to diversify here. (It's like founders selling 20% of their stake at IPO and buying an index ETF with the proceeds)
I think this would be different if an engineer went to work for GOOGL at age 35. At that point their assets would be diversified across various equity and/or real estate holdings and the GOOGL shares would represent a large but not overwhelming portion of their equity holdings within their greater portfolio of assets.
I started with BigCorp at age 33, after leaving academia with a phd and equity measured mostly in magic: the gathering cards. So, uh, yeah. Assets.
- (I don't actually own any M:TG cards, which I use here as a glamorous stand-in for my actual hoarde of obscure tabletop RPG's, bits of electronics that could one day be synthesizers, and books about representation theory.)
I think this would be different if an engineer went to work for GOOGL at age 35. At that point their assets would be diversified across various equity and/or real estate holdings and the GOOGL shares would represent a large but not overwhelming portion of their equity holdings within their greater portfolio of assets.