I guess that's true but put yourself in the position of a major fund manager. Would you rather explain "We lost 3% this year because of a dumb IPO because we track an index that includes dumb IPOs," or would you rather say, "We lost 3% this year because I decided, as a passive fund manager, that the index was wrong and I knew better"?
Your career would be over.
Or at least, you would have to transition over to an active fund!
No, that's not how it works. The resource managers who hire and promote fund managers are well aware of how trading large blocks too quickly can skew pricing. No one expects performance to exactly match the index. Read the prospectus.