What's up with modern music in ballroom dancing?

Why do they play modern music in Dancing with te Stars instead of actual songs that match the style of dance they are portraying? And I know one of the main reasons is because of ratings, but do any dance professionals out there agree that it is a desecration to the art and culture of ballroom dance to dance to music that clashes with the different styles of dance? For example, in Dancing with the Stars tonight a waltz was danced to "My Heart will go On"...isn't a waltz played in 3/4 time?? Not 4/4!?!? Last week they danced a Samba to a country song! I can go on, but where will I end?