It's a scary thought, but it's undeniably true: If someone like John Lennon, or Janis Joplin, or Bob Dylan showed up on a singing competition today, he or she would be kicked off. No one in the trio would have the sought-after technical singing abilities to advance in a competition (can you imagine a soulful, but nasal, singer like Dylan taking on Whitney Houston?), and, none of the three, if they showed up on American Idol, would have the looks to get any votes. It's a different time for music.
Also, just to wade into the YouTube comments for a sec...
YOU DON'T FUCKING SAY.