They were primarily setup to avoid another great depression. They are operating under the assumption that the great depression was caused by a general loss of confidence in the stock market (and other types of investments) and that if they insure confidence, it will never happen again.
They don't really care if an individual investor loses money.
But pump&dump schemes prey on inexperienced noob investors and are very effective at pulling all their money away to experienced pump&dumpers. The SCE are worried that many noobs will experience such a scam and decide that investing isn't for them. This deprives the sock market of funds which the SEC considers bad.
As for GME and WSB... well the SEC are in a bit of a tough spot.
In general the SEC wants the stock price to match reality, and WSB's short-squeezes are clearly violating that. But if the SEC does anything to drive the share price back to normality then it looks like they are siding with big hedge funds and that really reduces the confidence of retail investors.
I suspect they might eventually enforce a technical solution which provides live updates to the current status short positions. Such updates will mean that short squeezes can operate on the actual intelligence of short positions, rather than the wild speculation they are currently operating on. On the flip side, shorters will use the live updates to know when they are at risk of a short squeese.