Umm no they weren't. This is one of the dumbest things I have ever heard.
Just because they were popular doesn't mean they weren't releasing the most ground breaking music of their time.
Listen to in order: Rubber Soul, Revolver, Sgt. Pepper, Magical Mystery Tour (maybe Yellow Submarine) and then Abbey Road and tell me that wasn't the most progressive 5 years in the history of music, especially compared to what was going on at the time.
To even compare them to Bieber shows you have no idea what you are talking about.
My name is Nicky, but you can call me Dre.