Is it? Think about this:
Shojo is mostly known for relationships and pretty characters.
Does that sound like shonen-ai too?
Also, check out this thread. My mule (Miori Hikari) and a bunch of other people argued whether or not Yami no Matsuei, Gravitation, and Loveless are actually "mistaken" for something other than shojo.
Shoujo does not always equal sugary romance
Please discuss kindly (unlike that thread in which page 183 erupted mass arguments).
Please note- yaoi does not count cause there is male sex, which shoujo generally doesn't have.