No matter how many MMOs demonstrate that people using vanity systems for pure bikinis are a small minority someone will always bring up this tired implication
This part of his post I could support. Vanity systems aren't for everyone and a simple "toggle vanity off from my PC's view" option should be easy to add. If he (and those like him) want to view everyone their Rainbow Pimp Gear while everyone else sees people in their Vanity Costumes that's his business.
Even better it could prevent pointless restrictions like "no vanity in PvP". Those players that consider needing to see an opponents true gear a strategy could off toggle vanity while PvPing while players like me still get to see my characters in the costumes I want in PvP.