I won't invest in any ICO without a prototype. The risk of being scammed is well too high. How many ICO's don't even have a MVP ? More or less 90% ?
With a prototype, we can expect the team to manage and fully develop the product described in the whitepaper.
Before ICO's, every startup that encountered the success would have developed a high quality product. The product was tested by the public and now ?

Most people just following ICO for the word spread which is too hype for it, and others an ICO with the refferal system, which is there's a lot of bugs inside.
People always trying to cheat to get more and more value in every ICO they choose
True that! In a future there wont be super high bonuses. ICOs should have a prototype, traction, community.
Hype can hurt a project.. Hype = speculators.
Thats why I believe in Crowdholding. These guys have a working product, low hype and real community.