Call of Duty is a great game, Eminem is highly overrated, and Bieber does have a good voice, just really terrible lyrics and melodies.
On the other hand, of course lyrics matter to a song.
So on three out of those four, he's fine. As long as he's not going around claiming Bieber is a better singer than Bob Dylan or Call of Duty is better than, say, BioShock, he's fine.