As the OP is asking about the remake being considered 'Racist', my take would be Yes in today's world.
Agree it is based on a real person, but that won't stop those who would be offended.
Probably the same reaction if someone did a remake of 'Gunga Din'.
On the question of why do a remake of a Classic, I often shake my head and ask WHY?
Are there not any good screen writers left in Hollywood, or has everyone run out of ideas?
How about choosing a new Novel to make a movie about.
Most remakes are a miss in my opinion; can only think of a handful that seem better than the original.