how come radio stations just play the same songs on a continual loop now

[c=7700B2][i]the few radio stations which play 60s 70s and 80s music, just play the same playlist, the same songs on a continual loop.....nothing alternative....for example, if they play a beatles track they will play that same track over and over, 'strawberry fields forever' and no other beatles songs?

why in the hell do they do that? it's so god damned annoying.[/i][/c]