Why do people call Millienials, Millenials, instead of Gen Y?

They're technically Gen Y. They're after Gen X and Before Gen Z?

Why do people call Millienials, Millenials, instead of Gen Y?
Why do people call Millienials, Millenials, instead of Gen Y?
Why do people call Millienials, Millenials, instead of Gen Y?
Post Opinion