One good reason for suggesting a friends and family round is networks are a valuable ingredient of success.
So a good filter for an investor faced with uncertainty is to see if you have a network and can convince someone in it to bet on you. Your network has more information about you than the VC does, so your network's judgement of you is a useful signal.
Instead of taking the advice literally and trying to figure out how to build a network to signal quality to investors, he is going to assume it's just racism in which case there is no reason to do anything because nothing can be done.
That is a real shame.