If they're following footsteps of MCU, it doesn't seem like they're doing it much accurately (from a fan's perspective); they're jumping into Justice League as if they are microwaving a meal, rather than slowly cooking on the stove and introducing their characters first in their own respective movies.
The trailer itself looks nice, however!
Also who is the villain in this? I don't recognize the big axe/hammer wielding fellow.
Steppenwolf. The villain, not the band.
I did a quick google search on him and he's kindove...meh. He's linked with Superman right? I was reading a short bio and I don't know, to kick off a "big" movie franchise like Justice League it seems like an odd choice as the first villain in it.
To be fair - and you can correct me if I overlooked the point you were making - but they did introduce Black Panther and the new Spider-Man through Civil War before their respective movies came out, so Marvel is guilty of doing that as well. I personally don't agree with that kind of tactic same as with you though, cause I think it would have given consumers a good idea as to each of the characters personalities before going into it.
Also who is the villain in this? I don't recognize the big axe/hammer wielding fellow.
The first villain in The Avengers series was Loki.