Who wouldn't want to be as sexy as a vampire?
"Wannabe" is a slang and insulting term for a Ghoul, a human servant of Vampires. Many humans are actually perfectly willing to become Ghouls, for it can mean a greatly extended lifespan (and even cure many diseases which even 23rd-century medicine can't tackle) without most of the drawbacks of actually becoming a Vampire. Others volunteer for the post in the hopes of eventually becoming a Vampire themselves, for a chance at true eternal life and even greater supernatural powers. Nearly all of them end up regretting the decision, for it means total obedience to a Vampire master who generally treat their Ghouls like disposable slaves, walking larders, and chew toys all rolled into one.