Declaring that someone owns property, makes money from property and is part of an "old money" family is not character assassination. Nothing is implicitly wrong with any of that.
Declaring without proof, is one part of the obvious character hit. Further, being part of a family isn't evidence of entitlement to said wealth.
There is most obviously a negative implication there, and it isn't subtle: that the VCs (in this case Andreessen specifically) are harming non-wealthy people in places like SF by intentionally driving up land values for their own benefit. The countless front page stories on HN in the last few years about this specific topic, make it more than a little bit clear there's a negative association in place.
And if you want to get really close to a very serious legal charge, here it is: it's being blatantly implied that Andreessen is conspiring with very wealthy land owners, knowingly against at least some of the interests of his own investments through Andreessen Horowitz, for his own personal gain. How is it against the interest of said investments? The claim is he's involved in intentionally driving up the value of real-estate, which drives up the cost of living in eg SF, which makes it more expensive to retain and lure talent, which harms his investments (lowers their odds of success in numerous ways, lowers their margins by raising costs, etc). That's an extremely serious accusation.
You are defending a person who doesn't need defending. Or are you defending your side of the (non-) argument and can't accept being wrong? (Only as wrong as presuming slight, the description of the business strategy could have been a compliment)
You are hanging onto uncommon cases and what-ifs. What if this mega rich Venture Capitalists doesn't have to his family's real estate wealth and doesn't have any of his own? Doesn't matter, you are yelling and arguing with me like it affects me. I just swooped in and pointed out one fallacy, now I am swooping out because this doesn't affect me.