You forgot that those "investors" are always looking for easy money. And because of that they don't see ICOs as a way to help and be part of a promising project, but a quick way to buy those tokens cheap and dump them after the release of the project. That's why they blindly invest in all new ICOs in the market.
Yes, they can't really control them. But the same way the US government wants to protect their citizens from fraud schemes by going after them, they could go after ICOs because they are not regulated and most of them only care about the money collected during the crowdfunding phase.
Do you really think those governments should just let those schemes operate without any control and just say to their citizens "if you don't want to lose money, don't invest in scams" ?
So you'd like everything to be regulated by the government, because there's a possibility that you could lose money, get scammed, cheated or hurt in any other way.
The government should surround you in a protective layer of foam, so that you don't have to think anymore and if anything happens can run crying to your
mommy officials.
Not all ICOs are made to scam you, just as not all casinos are cheating, not all people are lying and so on. You need to use your brain and do some research before throwing money in someone's face.