Richard Wagner was a rabid antisemite and as some as his contempories remarked "not someone you you want to invite to dinner". However, does this negate his obvious musical genius.
Thomas Edison used to tour around the US electrocuting dogs and puppies to "prove" that his DC power was safer than the AC power advocated by Westinghouse. Does he somehow lose his talent because people shouldn't like him?
Should we demand that famous people have absolutely perfect characters? I think not.