I believe that, overall, Malcolm X was good for the black community. Despite embracing some pretty radical beliefs in the 1950s such as black nationalism and black supremacy, I believe that Malcolm X's words inspired the black community to feel as though they no longer had to take their cue from white society; they no longer had to feel pressured to fit in in the way Dr. King imagined.
I come to this conclusion largely from an observation by James Baldwin, another civil rights activist, who wrote that the black man is only truly defeated when he begins to believe what the white man says about him. I believe that Malcolm X's radical candor pulled those who were closest to succumbing to that mindset away from it. He gave the average black citizen a reason to be proud.
This is, of course, all subjective. A case for this question could be made from either perspective.
I think Malcolm X's idea of Black Pride was a step forward in the idea that being black was nothing to be ashamed of. I do not think the violence or militaristic approach was helpful to the overall cause or civil rights movement though.
This is, of course, a matter of opinion. There are certainly ways to argue it both ways.
If you wanted to say that Malcolm was good for the black community, you could point to his black nationalism. You could say that his emphasis on the idea that blacks were as good as (or better than) whites was good for the black community because it helped to instill them with much-needed pride.
On the other hand, you could argue that Malcolm hurt the black community with his militance. You could say that he projected a very negative image to white America. This, you could argue, helped to push the races apart. You could contrast this with the way in which Martin Luther King, Jr. worked to bring the races closer together.
So, you can argue this either way. You should choose which of the two sounds more plausible to you.