I agree, the trailer is underwhelming in telling me what the film is about, but at the same time I've already been sold so I don't want to know too much about the film. I can easily see non star wars fans seeing absolutely nothing in the trailer because it's devoid of any sort of plot.
I disagree that the trailer is devoid of plot. This is what I've gleaned from the trailer:
Rey: she lives on a sand planet, and seems to want to not be there, very Luke esque. Probably hates Tosche Station. Something sets her off on a journey of discovery. That's a plot point.
Finn: used to be a Stormtrooper, he arrives on a sand planet. He obviously meets Rey, as we see them together, and they join together on their journey. He seems to be lost, and looking for himself. He is directionless, leading to external conflict. That's another plot point.
Kylo: seems adamant on continuing on some kind of "legacy" he feels Vader left behind. He looks to be the antagonist of this, and unlike Rey and Finn, his plans are far grander (they want self discovery and meaning in their lives, he wants something that has galactic repercussions). That's another plot point.
General: the Jedi and the Force seem to be the stuff of legend. Rey and Finn appear skeptical of the tales of heroics from before they were born, whereas Han is now a convert, acknowledging that the Jedi and Dark Side are real. The Force seems to be actively drawing these characters together that will naturally cause a conflict between Kylo Ren, anyone he's allied with, and heroes like Han, Leia, Chewie, and new guy Poe, who is a Rebel Pilot. That's more plot.
All of that can be gleaned from the new trailer, without having to k i.e. Any of the history and story of Star Wars. All of what I posted above is contained in this single trailer, either implied through visual cues, or outright spoken in dialogue.
The fact that people claim a restrained trailer like this is lacking in information and plot points, are the reason why filmmakers beat us over the head with plot points in modern trailers and films. It's like some folks want an "In A World...where the Jedi are a myth, three heroes will rise, to defeat the forces of darkness...Star Wars!" It's just not necessary to be handheld through a film's premise. This ain't 12 Monkeys, it's Star Wars.