Back in the olden daze, dirt bikes were mostly two-strokes with the drain plug handling the draining of the transmission oil, and the drain plug was located more toward the center of the crankcase.
The WR-250R/X drain plug is positioned more to the left-hand side.
The stand manufacturers are simply making them the same ol' way.
Why not keep the stand for the times you need to get the wheels off the ground, like when lubing or adjusting the drive chain, changing tires, and disassembling the steering head and rear suspension for greasing it?