He wasn't making the case he isn't harmed. He was making the case that the effect isn't large. You don't appear to understand the claim itself, let alone the reasoning.

Just because you don't understand the basics of the financial system, or the different indices, or the amount of money flowing into the funds that track each, it doesn't mean others don't. The impact if it had been included in the S&P500 would have been at least an order of magnitude more than just the nasdaq 100.