They serve their purpose well, IMHO.
I used to think "Whats the point in that" also, but when you look at the Radio Stations you simply cannot get with normal Radios, and instead of going out and paying massive amounts for a DAB Radio, having it in the Digital TV Subscription put my mind at ease.
Once Scuzz left the EPG, I was stuck to find a decent Rock Channel on Virgin. Luckily the Radio Stations were still there, and the recent news that Planet Rock is staying also, is welcome to me!