You know who does a good job of delivering the lines required for an advert which isnt trying to leverage star power and simply requires words to be spoken (You dont even need them there, have a hand model manipulate the phone)? Voiceover artists.
Oh grow up. The idea that if you cant do better, you shouldnt criticise is pathetic and childish. You dont need to be a professional chef to know when a dish is burned.
Yes, neither of them have particularly memorable voices. Do you not remember the slightly odd moment during the Keynote when the adverts were played, Tim asked does anyone know who we got to do these and there was total silence in the room. These are not memorable voices.