Earlier quoted context omitted.
On a fundamental level, the S&P 500 index is meant to be a benchmark of the market. Journalists, policymakers, investment managers, politicians, regular investors, everyone I know all use the S&P 500 as the benchmark of the US stock market. If a significant percentage of the market is excluded from the index because they don't meet index inclusion criteria, then then index stops being a useful benchmark.
It’s a benchmark of the market under certain rules, like having multiple quarters of earnings for the market to value them at. These companies want special exceptions. If you are an exception why should you be included in a benchmark? At best they should have an asterisk against their name like Sammy Sosa or Mark McGuire if they are not following the same rules.
The profitability requirement is something made up by the S&P committee. If that rule ends up excluding trillions in market cap, the rule has defeated its own purpose. The 12 months of profitability requirement punishes high-growth companies that invest their FCF into growing the business vs taking profits.
It excludes companies like Amazon, which when ran by Bezos, was famously unprofitable and invested all free cash flow into growing the business and never turned a significant profit until >20 years after its founding.