I have to agree with you. I always took a very conservative approach and divested my company shares in order to diversify, even before I retired. In my case, the pain came not from stock losses, but from their gains. I "lost" so much by selling shares too soon. But now I am diversified and can survive a loss of my holding in my (former) companies shares (I still own some).
Decisions can only be judged in the context within which they were made.
Diversifying is a wise move for strongly mitigating downside risk.
One of the wisest and thoughtful people I know was a long-time and early employee at a major tech company. That friend did exactly the same thing, diversifying early. It is difficult to overstate how successful he has become in life; success need not be measured in dollars.
Right? If we judge every decision by the actual results instead of the information we had at the time, everyone made a stupid decision by not buying a lottery ticket that had the correct numbers on them yesterday.