Grant Gustin as you know is the star of the hit CW show The Flash. The show is critically acclaimed and has lots of fans. When the announcement of Ezra Miller being casted as Barry Allen as the Flash for the DCEU (DC extended universe) fans weren't to happy that he was casted. Fans weren't just upset with Ezra himself being casted but the fact that Grant wasn't casted for the movies. Grant has been doing an amazing job as portraying Barry Allen on TV, he brings lots of life and joy to the character. It's understandable why people would want him to be in the movies, but Ezra Miller will do an amazing job as the Flash, we shouldn't worry at all about him not being a good Barry Allen, Grant Gustin thinks this too. This is what Grant had to say on Twitter.