Again, it's a business.
If a market finds it makes much more money per square foot on wines than on beers, they will likely reallocate some of the aisle space to the more profitable items.
The same happens with radio. Clusters are adjusted to provide combinations of salable demographics. The best case is LA's "wall of women" with KIIS, KOST and MyFM. The three can sell separately, but they are programmed to be sold in a pair or a trio for more dollars for iHeart.
A station that can't be sold in a cluster package will benefit less from synergy and thus reduce cluster billing.
Going back to supermarkets: which one do you go to... the one that has some of your favorite brands or the one that has them all?
Coming back to "It bills well" as being offensive: actually, it was a (weak) DEFENSIVE posture to anyone who suggested AMP's 6+ numbers were low and getting lower and that a format change should be considered. As I recall, AMP 103.3, Mix 104.1, Magic 106.7 were Entercom's Boston "wall of women". I understood that to mean these three stood together in target audience and advertiser preference. Now that "wall" is only 2/3 of its original size. Any thoughts on that?
And once more for the record: I don't listen to FM radio in Boston; it offers me nothing (except for maybe WCRB when I want some relief from the talk on AM). So I was NOT one of those advocating for a change of format to 103.3. If anything, I missed what used to be Oldies 103.3 WODS, but EVERYONE here told me to get over it because that ship, carrying away those of us in an undesirable (age 65+) demographic, sailed out to sea.