Marketing lol. A lot of people in the scene just get fooled by most of the marketing stunts by the projects. Either it's by hiring big names (more on streamers really) as their advertisers and/or tying their project to an existing aspect of the internet that's REALLY famous. It's basically free marketing for that part really, and includes them trying to spread the name making people "think" that it's a legitimate one.

As for identifying projects, there's nothing really solid about it unless you're part of the team. You're almost always going to end up with assumptions over assumptions. Most people just inevitably look at the project and check its state, check the economy, and make their own judgments. As for how to know which info leads to it being final or not, it usually varies from person to person since there's no set formula for an answer.