If Britney bothered to sing live and get a vocal coach, she could have made something out of her voice. Look at Rihanna, she started nasally and a mess, but now she's got some amazing power and clarity with her voice. Anyone can improve, but Britney didn't even try.
That's why she has to jack up the autotune on all her new music. And fans get excited at any chance to hear her live. They praise her for mediocre (at best) vocals just if they are live.
