My first flight was to the then new T1 Domestic, a haven of tranquility from a different age. Most were suited and booted. The bottom line is that Finance would turn round and point out the ROI on a dedicated facility for domestic was zero, indeed it would be a cost. They calculate, correctly, that for their business model to work given the current charging regime, they need to offset losses via driving footfall into retail and charging rent and/or taking a % cut on profit from retail tenants. Suggesting that this footfall is reduced isn't, pardon the pun, going to fly. They need to continue to drive volume through the shops and if that means a few less Q400s and ATRs then "Climate Emergency" take the train and make way for 189 Ryanair spenders. I get what you mean, but I can't see how it would make them any more money and that's the end of it if it won't. The only way to balance this out would be to hike user charges for domestic short haul and that's not a winning formula for the customer either.
CX Customer Experience isn't front and centre for MAG as they've got a critical mass in market and no direct competitor locally.