Professional wrestling generally isn't know for nuance or political/social sensitivity, and the release of Hulk Hogan's racist recordings hasn't helped to change this image much with the non-viewing public. To be fair, given the economic and social class associations associated with the viewing of professional wrestling (which, interestingly, do not reflect the demographics of the audience), has in many ways served as a handy excuse for this prevailing attitude.
In short, one gets a sense that specifically because it's professional wrestling and (mis)associated with the working class, we can't and shouldn't expect better, which it itself classist and problematic. WWE is now a publicly traded company, and this status reflects both a desire and a need to appease shareholders. This live-action analog to the original Muppet Show needs to think about dividends, for now.
When the WWE officially made all of its programming PG rated, the company has opted to rely on what they believe works financially and what doesn't create controversy. This is complicated by the fact that Vince McMahon has yet to give up his central role in booking and storyline creation, allowing newer, fresher booking angles to take hold.
As audiences can and have pushed for characters, storylines, and portrayals that better reflect the diversity of ways-of-being in television, film, and other media, this has sometimes created an economic incentive for media producers to listen and adapt. Even WWE has had to deal with fan backlash compromising their long-term booking, as was the case with Daniel Bryan and Roman Reigns.
With the WWE, audience demographics and its status as a publicly traded company have resulted in booking decisions that arenperplexing and reflects the unwillingness to break from its history. Fans have supported characters and storylines with non-white characters, as has most recently been the case with the wrestling stable The New Day, but despite their popularity or "overness," they are largely relegated to the Tag Team wrestling division, which has not and will not serve as a central focus of the promotion (Dwayne "The Rock" Johnson is a complicated but relevant counterpoint to this).
Where does this leave non-white wrestling characters? In most cases, they remain in a supportive rather than central role in booking and storylines, a continuation of the status quo and pre-public days.