Most ICOs have almost nothing in common with cryptocurrencies, other then using a smart contract over a some relatively primitive blockchain. They are generally startups, looking for funding. Most ICOs are indeed fund raising events, using future potential returns anticipation, expectation or promise as a mean to get such funds now. This kind of activity (get money today for some promises in the future), among in general honest crowd, also always attracts scammers, fraudsters and other indecent people, since their can and used to use plausible deceits to get some easy money. And the hotter the market is the easier it is to defraud a client. Toprevent such harmful activities, it has to be either self-regulated by the market participants, or self-regulated with the market environment (protocols), or regulated with some professional authorities.
I think you are making an important point here. When discussing possible regulation of cryptos, we always have to specify which specific aspect of cryptos we are talking about.
Regulation can mean taxation of profits made from trading, regulation of exchanges (e.g. concessions and capital requirements), ICOs (e.g. transparency requirements), AML and many more.
I personally believe that regulation could make sense in some areas and ICOs are one of them. As you said, they are often not more than start-ups that look for financing. A lot of them will use aggressive marketing strategies to get their hands on investors money. While you could argue that an individual should always be able to assess risks by doing its own research and then be accountable for it, in reality there often exist information asymmetries to the detriment of investors. This is exactly where regulation could step in.