[sk55]

Though your statement may be "true", you're missing the power play in the situation. Startups ask VCs for money. Send a letter out like this, and you're not getting money from them. The point isn't to be right, it's to get money and if as a founder you go against that goal, I would consider it irresponsible (unless you think strongly that this specific VC is damaging to your company...but then just choose not to take money from them instead of sending a rude letter).

If it was the other way around, you have tons of traction and investors are waiting out the door to invest then you might be able to say that. But in the end, I feel like it still does no good.