> They weight by free float so it would been something like 0.3%. Hardly the end of the world

That's one way to look at it. At a personal level, it's a small sliver and if it were to drop, its influence on your balance isn't much. So that's true.

Another way to look at it is that with ~200 million people owning index funds, all their funds balances together, even a tiny fraction of a percent is a massive amount of money being force-fed into spacex, which is to say, mostly into Elon's pocket (since he owns vast majority of the shares).

So why is it fair to change the rules to give this massive wealth transfer to Musk, who certainly does not need the extra money?