"Just" is doing a lot of work here.

Many people have appreciated gains locked into their indexing products such that changing is very expensive.

The biggest issue is not SpaceX/Elon per se, but indexes bending over backwards for him and changing their indexing rules to fleece index investors.

Most IPOs perform badly, to the point where the SP500 excludes all of them for a year, and I think that is actually appropriate for an indexing product. Though they're looking to change that and their float weighting for Elon.

Though after doing some digging I am not personally meaningfully impacted since Vanguard uses CRSP, which is float weighted, so only 0.1% of that is going to be SpaceX and I can live with that.

I short the stock on the actual financials if I was exposed to it (and it was actually possible), but it's a small float and there are apparently tonnes of Elon fanboys propping up Tesla beyond belief already so I expect this to be one of the hardest to predict stocks/IPOs.