Sometimes, the cultures of a race can differ significantly, to the point that sharing the same base ability score interferes with its design. The PH formula for race design is too rigid. It imposes +2 base and +1 culture, as the only way to design a race. This unflavorful grid-filling symmetry seems a mistake.
The UA Gith race design tried to break away from it. It had +1 Intelligence for the base, and then assigned +2 Dexterity for the Githzerai culture and +2 Constitution for the Githyanki culture. For this particular instance, the Gith, I can live with it.
Race design benefits to be more free form. The artificial symmetry that forces all cultures to have exactly the same base seems a wrongminded approach.
Even the PH breaks out the +2 +1 design, at least a little bit, to assign Strength +2 and Constitution +2 to both the Mountain Dwarf culture and the Half-Orc hybrid, to buttress their race flavor as excelling as warriors, strong and tough. Probably, they should have gone the same route with the design for the High Elf and assign it Dexterity +2 and Intelligence +2 so it can excel at wizardry.
In any case, I hope future designs care more about mechanizing the official flavor of a race. More free form mechanics. Less flavorless grid-filling symmetry.