The comparison/debate is unnecessary to my mind. They're different. That's all I keep saying. My Ranger is different than my wife's little compact cube car thingy too. LOL I've got a lot of different chairs around the house. They're different. I could go on and on, but there's no point.
Just because they are both Kubotas, both cost about the same, both are intended to do some work. Just as a fancy F series mower or a skid steer might also be about the same price and all of them, all of them might have that same 1 liter Kubota diesel engine. You might find 4 or 5 different machines at a Kubota dealership that cost about $14-15K and have that same engine. But they're all different and targeted at different buyers. It's really that simple. Shoot, there's likely a Kubota RTV with roughly that price and possibly that same 1 liter Kubota diesel engine. So?
Buy what's right for you and your tasks. That's precisely why Kubota makes all these machines, with the same engine, at about the same price point. B, BX, F series, Skidsteer, RTV.