Heathen,
If only you were right.
Look behind many of the most successful rock bands today and yesterday and you will find that it is the cover numbers, or songs written by other writers have given them their following. It is often a surprising, but valuable experiment to trace the music to its roots, often you will find it belongs to others. Some of the poorest songwriters in monetary terms that I know of are also well known for greasing the careers of semi-talented, though admittedly more confident musicians.
As Hunter Thompson once wrote : "The music business is a cruel and shallow money trench, a long plastic hallway where thieves and pimps run free, and good men die like dogs. There's also a negative side".
Everything is everything else.
HS