Most ICOs stipulate that in their T&C that tokens are to be regarded as without value. Yet they put up a big dog and pony show about selling them. To think that this absolves them of responsibility is a bit naive, in my opinion.
This particular token is a clear cut example. Block.one will build another altcoin. There is no code yet, only a whitepaper that on the face of it seems to promise the impossible (all the functionality you can think of at a million times the throughput). To finance this they will sell this EOS token, which is explicitly stated not to be exchangable for their future altcoin product or have any other use.
It might be of interest to note that the person behind this is not new to the game. This is his third crowdfunding scheme, and the first two products are far from what was promised. As to why people invest your guess is as good as mine, but the greater fool theory is a good starting point.
So what is it exactly? What are you buying?
(1): https://itunes.apple.com/us/podcast/unchained-big-ideas-from...
https://www.irs.gov/uac/newsroom/irs-virtual-currency-guidan...