As someone who has made a statement that somewhat resembles what you are implying I wanted to chime in.
I have said a few times either here or on the E Mount Full Frame forum that when comparing IQ on the Rx1 to the A7R with Loxia 35 lens that each have some advantages.
The RX1 being superior at close distances and wide open at all distances.
The Loxia on the A7r starts to show advantages over the Rx1 at longer distances, the detail is much better in those cases, which would usually be an F8 - F16 situation.
Now, I never said it was because of the lens itself, could easily because of the 36MP sensor in the A7R compared to the Rx1.
I do think the A7R and Loxia 35 is better for landscapes but not by much and that option costs more and is much larger in size. Rx1 has other advantages such as Macro ability, silent shutter, etc...
I also never implied the Rx1 is not a great tool for landscape photography.
The new RX1 II will I imagine will likely be better in all aspects of photography than the original A7R and the Loxia 35 lens combo.