There is surely a good reason for it, but I don't know what it is. I have a G1900 mower and BX1860 and they both have the same setup. The brake pedal is too high and it's awkward. Why not move it to the completely open left side?
From a standpoint of safety - it is really hard to ease close to something while tapping on the forward or rear pedal WHILE trying to make sure you do not get too close by using the brake once you let off the F/R pedal when they are on the same side.I've had a 2008 bx24 (brake on right) and a 2015 bx25 (brake on left). I have to say that the right side is more intuitive / car like. I prefer the brake on the same side as the Forward/Reverse pedal.
I grew up farming as well, but find "turning brakes" pretty much useless on any of mt HSTs with R4 tires, I can use them with my cruise control, just useless. I still use turning brakes on our geared tractors with Ag tires.I had noticed the pedals on the right. As I am farm oriented I couldn't figure out why with anyone would want this with turning brakes. Looks like a recipe for disaster to me.... My older tractor has the brakes on the right, but it is not hydrostat.