No more then the "smart-animals" BS. One of the definitions of a species is that the offspring are fertile (this is why donkeys, Ligers, and Tigons are sterile) meaning, unless genetics work way differently in this world, for a person to have an elf back in the family tree humans and elves are effectively the same race.
They're definitely not the same race, and I would classify these elves as homo-sylian. Much like homo-neanderthalensis, we can have children with them, but we aren't classified as the same species. We are however, the same genus, the homo genus.
And much like the Liger, Drow x Human breeding result is deformed and often fertile offspring because they branch the furthest away from humans due to isolation in caves (and likely plenty of incest since they lived in small familial groups). Drow can however have healthy children with other elves, but it's very rare.
Well, 'species', not race, but whatever, speciesist doesn't really have the same ring... XD
Normally, I guess we could blame it on magic, not genetics. lol
Unless it's like literally a fireball, using magic as an excuse is almost always a bad idea. Even magic needs laws. If it can't be explained, it's bad storytelling.
Even the Hulk has an explanation, even though it's not actually possible.