Earlier quoted context omitted.
It wasn't necessarily the right move. He/she likely had asymmetric information about where Google was going and how likely it was to continue succeeding. If they couldn't sufficiently exploit that, then that's on them (assuming they had access to all the relevant metrics). It's great to diversify, but blindly selling isn't some sort of virtue to optimize for...
depend, as I wrote above. If I give you 2 options. 1) $300K in GOOG 2) $300K in cash if you dont believe that using all of the $300K in cash to buy GOOG immediately is the smart move, yes, you should be blindly diversifying.
If you can't leverage the asymmetric information about your company to make a competent buy/hold/sell decision then yes by all means diversify it all.
I just want to make sure the point about asymmetric information is clear though. And it's more relevant in private companies than public ones.
If you're not willing to buy and hold private company equity even after having access to asymmetric information about the firm, then you should consider leaving the company entirely. If you don't then that defeats the entire purpose of taking a chance on a private company and being compensated in equity which can't be acquired through traditional means. You're accepting the equity presumably because you think it's worth a lot more based on the asymmetric information and market opportunity.