I'm suddenly getting this horrible feeling that this whole movie was basically designed to be DC's answer to GotG and that thought fills me with a mix of terror and sadness.
That's because this is what the actually is.
DC saw that, took a bunch of almost unheard-of B-Listers in a team somehow related to the main characters (much like Guardians of the Galaxy), a bunch of criminals with strange pasts, forced to work together. They probably thought if GotG can do it, so can they ... they just seem to forget that the main drive of GotG was the randomness of the movie, the music, the really disconnected characters forced together, the humor, because let's face it, it was more of a comedy than an action movie, yet a full-on space opera, and more than that, this movie had feelings. It has a heart and isn't afraid to show it.
... Suicide Squad is full of scowling, grimness, and guns. The only colorful part of it seems to be the Joker and Harley Quinn, and that seems to be their main selling point. They don't even appear to market the movie with Will Smith's face !