There are logical reasons.
You're looking at share... in this case, of course KRBE is above in Mornings at this point with no morning show launched on Hot yet (until the 21st). Then you'll see a massive increase in share due to the increased TSL. Mid-Days can be reasoned by the fact KRBE is extremely dayparted and sounds near KHMX, and is more "work-safe" than hearing rhythmic songs.
Afternoon, Nights, and the whole scope is covered under the blanket, as you had mentioned, that Hot is still in it's infancy. If you take a look at Cumulative data, Hot is not "that" far behind KRBE, and is actually over in some demographics and dayparts.
Apparently someone agrees with me, I've heard ads that Bikini Beach, Club Roxy, and Drink Houston are all on Hot now. Think outside the box and factor in the lower rates, and you'd probably not oppose advertising on Hot either, seeing it's huge growth in just the almost 4 months it's existed.