I'm not familiar with him, either, at least by name. I've seen a few of the movies that someone said that he's in, so maybe I'd recognize him, but I can't put a face to his name.
It doesn't have to be. It's simply a matter of fans wanting beloved characters to stay somewhat consistent and recognizable. For over 70 years and two dozen movies, James Bond has been Caucasian. It should be easy to understand why people would like him to remain that way.
If we were talking about a reboot of Beverly Hills Cop, would you support the casting of a white actor as the new Axel Foley? Ethnicity isn't that important to that character or those plots, either. In fact, Sylvester Stallone was originally going to play him. Is it wrong to want Foley to remain black?