I don't have a lot to add (or much time), other than to say I have no issues with half-orcs as a concept, although the wording in the PHB is ****. I dislike the whole concept of every race just being just a rubber mask you put on a pile of stats, I think it takes away from the game. On the other hand I don't see it changing, and yes, I've take advantage of floating ASIs because whether I like it or not it's here to stay.
However, I do always find it odd that people insist that because we have half-orcs that orcs and humans must be related species. It's a world of magic, one where we have hybrids of humans and horses, humans and bulls. Not to mention the monstrous mixes of completely unrelated species. I don't assume genetics works the same way in a world where someone can twiddle their fingers and cause a ball of fire to appear.