lovebwy-
It's both. and more.
People love to think that decisions are uni-dimensional; they almost never are.
Yes they like the prestige aspect but they also like the money.
At least until Comcast, both NBC and CBS liked being New Yorkers. (ABC less so.) And very few events are as quintessentially NY as the Tonys. (I guess the Macy's Parade which is on both.) My guess is that NBC would still jump at it if given the chance, especially since it is a "neighbor" now.