And I don't understand how that can be possible. Genasi fill their niche of being elemental/half-genie people. Tiefling fill the niche of being fiend-touched people. If I ever get the chance to play another character, I know that there will be dozens of races more appealing to me than Genasi, Tieflings, and others, but there's a difference between "I find this race appealing for a PC" and "I find this race appealing as a fantasy race for the game/my world". Genasi are interesting to me from a world-building perspective (as a sort of ambassador/messenger/trader race between the humanoid races and genies, and people that have conflicted opinions on both sides of their parentage). Halflings are simply not, for the many reasons that I've outlined in the OP and throughout the thread.
I don't find genasi appealing as a race that I could play for a future character, but I do find them appealing as a race to populate the elemental planes in my world and to fulfill certain themes that other races can't do.
It's not necessarily a bad thing that you don't want to play them (quite honestly, the more races that I don't want to play, the easier it is for me to play the characters that I want to, because I have less options to choose from), but it's typically a bad thing from a design standpoint if you don't want anything to do with them as a DM.
Probably. I've tried to be reasonable, but I don't think this discussion is getting/going anywhere.