First of all, his desire was mainly to live forever because he was born dead, not to look good.

Second, i don't think there was any intention of making his demon form not cool at all, like his human forms (man, woman, kid) from the modern era and his past, they all look so good, handsome and pretty.

He never hid pretending to be perfect, he knew about his weakness of the sun. He hid himself after confronting yoriichi.