Fathers can, and have, named their sons Ismael. So why would they not be allowed to name their son Esau? The reason for Esau and Ismael being similar is because both names are generally identified with as siblings of patriarchs that cause trouble and are undesireable.
Typically, Esau is portrayed as unfavorable in rabbinic interpretation of Genesis. I am not sure, but I would think there would be a halachic issue with naming a child after someone evil (I could not imagine that any Jew would be allowed to name their child, say, Amalek). This question is two fold because it asks a preliminary question, "Is Esav 'evil' or 'bad' in the Jewish mindset and is this falsifiable?"