Because you've spent an excessive amount of time researching it, talking about it, maybe even demoing it. I'm pretty sure you making Dreams threads is more iconic at this point than the game itself.
Of course you're the one who said that people don't know what Dreams "actually is", not me. And if that's true, the marketing team is at fault. It's had so much exposure by now.
I've been unbeknownst of how many threads Gribble has made about Dreams on this site, trying to explain what this game is really about. And while development and unveiling on the game has been secretive, there's no need for a top dollar marketing team to slowly unveil what this game really is about. It's from Media Molecule, well known for LittleBigPlanet, a platformer that encourages creation. Past demos, while vague, have shown creative capabilities. It's not that hard to connect the dots and figure out what kind of game is this in a general sense.
Lousy marketing team? Maybe. But one could speculate that if Media Molecule is the one dripfeeding information about the game, they have to work with what's given to them. I'm sure all the secretiveness is on purpose, nothing to panic for.