Whitepapers are to lure investors. Don't get me wrong, but many whitepapers are just full of bullshit and have very little value/ juice = technical descriptions, detailed info on devs plans.
This trend started few years ago, when people started saying that no whitepaper = scam.
Today I would say it may be exactly opposite.
Recently I was looking on Steem (Steemit.com) history and they started with no wallpaper of all, hell, they haven't even post description of their project.
That is the problem mate. Whitepaper is important but how if the whitepaper was made with no good value? Its useless.
So after this, whitepaper is not so important anymore but working product and good team is the most important one so always check those thing.