> There are people who want to invest in ICOs, Ponzi schemes
Ponzi schemes are fraudulent operations intrinsically designed to extract money from investors by misleading them. Slack is a software company with a cogent, well-defined plan to leverage unprofitability now into significantly greater profitability later. Not only are these things meaningfully different, they're categorically incomparable.
Even if Slack ultimately fails it has a reasonable plan of action that distinguishes it from fraud. The SEC does not exist to eliminate all risk from investor portfolios, that's impossible (and suboptimal!). It exists to (among other things) ensure the risk to investor capital occurs through the normal procedure of markets instead of outright fraud. For similar reasons most ICOs (and particularly fraudulent ones) are categorically dissimilar from a tech company going public at a net loss.
> others want to rape, murder...why should anyone’s opinions be forced on these people?
I can't believe I have to say this, but the two things you described are violent acts with directly violate the rights of other human beings. I'm not sure how much else needs to be said here. We started off at people being allowed to engage in risky but fundamentally legal and mundane investments, and ended up at fraud, rape and murder. Somewhere along the way we've gotten quite lost.