...feel the need to refer to Lady Gaga as Stefani? You don't call Rihanna "Robyn", you don't call Katy Perry "Katy Hudson", you don't call Ke$ha "Kesha Sebert" and you most certainly don't call Nicki Minaj "Onika".
Discuss.
Same reason you're referring to Nicki as Nicki Minaj.
...feel the need to refer to Lady Gaga as Stefani? You don't call Rihanna "Robyn", you don't call Katy Perry "Katy Hudson", you don't call Ke$ha "Kesha Sebert" and you most certainly don't call Nicki Minaj "Onika".