I suspect it's an easy way to get something that won't sound completely dissonant, especially because you can use the same blues scale over multiple chords.
I can see the logic behind that, but without any sort of tension/release between the melody and chords, it still sounds just as dissonant to my ears.
Granted, it will never win any awards. Part of the choice behind it might have been the desire to "ship" it before Christmas.