Indices are supposed to reflect a part of the market. That's why you have all of S&P500, the Dow, NYSE Composite, and Nasdaq Composite (and several others) in the US — They each reflect different attributes of the market as a whole.
As it stands, it's clear that the users of S&P500 are not interested in the performance of the parts of the market made up of overpriced (and potentially highly volatile) IPOs.
As it stands, it's clear that the users of S&P500 are not interested in the performance of the parts of the market made up of overpriced (and potentially highly volatile) IPOs.