I've had a lot of friends mention the last several days complain about the Joker having tattoos and a grill. Most of these same people complained about Heath Ledger getting cast as the Joker, and we all know how that turned out.
So what gives? Why is everyone losing their minds over a few tattoos that are almost gang related? Why does it matter?
The bigger deal that you should look for is that someone actually attempted to do something different. A lot of writers try and fail to recreate characters that have long storied history's in comics and in film. Be honest, the first 3 X-Men movies were terrible. So terrible in fact that they created an entire movie with an obscure plot line and tons of holes just so they could keep Hugh Jackman and ditch the rest of the story they'd created. The new concept of the Joker is just that, a concept, and they can change it back if they don't like it or it's ill received. But what's worse is when people regurgitate the same used materials over and over again, especially when it doesn't work.
Remember Superman Returns? I certainly don't. It was as if the writers and directors did everything they could to cast Christopher Reeves and replicate his movies. Reeves was amazing, in the 70s, but Brandon Routh is not Reeves. This was painfully evident as the director's only direction seemed to be "Brandon you're brilliant, in this scene I want you to be... Christopher Reeves!" The Amazing Spiderman films had tons of potential and high expectations, so why did they fail? Because it's the same Spiderman you always see, and a desperate attempt to reboot after Tobey Macguire ran the franchise into the ground. If Marvel were smart, or Sony or whoever, they'd lay off Spiderman for a while and let everyone forget that those movies even happened.
But back to the Joker. The Joker is being reenvisioned after 8 years when the late Heath Ledger knocked it out of the park. It's like when Facebook does a drastic update (remember timeline?) everyone is quick to overreact but once they saw it they got on with their lives. I get no one likes change, but you should appreciate that someone is trying to do something new and different.
The Suicide Squad could likely be the best DCCU movie to come out, it's a comic story that has never been explored on film, it has a strong cast and a great director, so lets not blow a gasket.
Especially when that's not the Joker you will see in the movie.