For me the lack of working product would be the first and only sign of a fraud project. Such times have passed when a project could scam people with a good whitepaper and original website. Investors are getting smarter.
as I know project trying to gather the funds using ICO is to realize or make an execution to their idea and thus resulting in a working product, maybe some of the projects out there are already having a working product even before the ICO being announced but it's still not right to judge a project as a fraud just because of not having a working product while the sole purpose of creating an ICO is to gather fund.
Maybe it's better to judge them by whether they are following their roadmap or not, although there are some other factors aswell.
But if satoshi could have a working product in the form of bitcoin and he did not received any funding, why new developers cannot create something new and have a working product or something close to it when this market is now so popular? It is not like they have to create everything from zero, they can look at the code of bitcoin and many other coins and find inspiration for their coin.
If this could be done 10 years ago why developers cannot create their coins without any funding? Why do they need so much money? The short answer to me is that the majority of those coins are scams.
my short answer is only one.
no developer as smart as Satoshi.
if all new developers have intelligence & honesty like satoshi, then ICO is no longer valid.