Some people are agreeing with you, but I actually don't agree. I looked into this and it's actually quite difficult to definitively identify who is being referenced. There are a few seemingly conflicting bits of info in the letter, like the person is a novice VC investor ("I recognize ---- is your first experience in venture, or as a professional investor") with the fact that they are also the lead investor in one of their rounds ("I still can't believe that is true for the lead of our Series ---"). As far as I can tell, these seem to be mutually exclusive: the leads of all the rounds seem to be veteran (or at the least very seasoned)VC investors.
Theoretically this would be easy to figure out if you had a yearly listing of board members which I imagine should be public, but that doesn't appear available publicly. The only listing of the board I can find is this news article [0] from 2015, but again, none of the people listed there can be definitively identified as the one being referenced.
As further evidence of how murky this is, several people in the comments below have named different people as the person being referenced. One commenter has edited their comment to change the person being accused.
If the author of this email wanted to point a finger at a specific person, they did a bad job.
[0]https://www.crowdfundinsider.com/2015/01/60650-lending-club-...