Why do they have to remove porn for the IPO?
Whether we like it or not, most investor money is ultimately managed by rich old dudes who want to save face around their friends and family. Since the US is prudish as all get-out, they don't invest in porn directly through the stock market.
If you want to invest in porn privately, I'm sure those companies will take your money and you can work out a payment scheme and contracts without involving the S&P.
I expect what the average investor actually demands is restraint and keeping porn out peoples faces so it doesn't become what you're known for. Don't become a "porn company" and don't show porn to people that haven't opted in or to children.