I do hope that half orc make into the game and I share the concern that allowing a half species of anything (which has always existed if DMs allowed it) makes all species into humans with cosmetic differences.
I can tell you this: I recently spent a whole bunch of hours playing (and for the most part enjoying) Age of Wonders 4. That game made the decision to turn pretty much any race in a cosmetic skin and everything about your faction is instead defined by a bunch of tags and secondary options.
Well, while some people praised the choice for "giving them freedom to be what they want to be" for a very sizable chunk of the user base it became one of the most controversial features of the game. The recurring complaint is that races in the game have no Identity and everything after a couple of maps blends into a certain... sameness.
I wouldn't be shocked if D&D would turn out to be directed toward a similar fate and people would start regretting asking for that degree of freedom in the long run.
