Why not ?
Each machine geometry has its own benefits / drawbacks.
For some guys the cartesian geometry is easy, simple, reliable and well known.
For other guys there is some kind of SCARA geometry which fits their needs more closely.
I started mechanical design of a dual arm SCARA because for me it has the following benefits:
Low part count.
No linaer rails, belts, spindles,....
Low footprint area.
Drawbacks are:
No linaer rails and therefore curved trajectories.
Nearly no firmware.
Arm droop.
There´s much more, but sometimes it´s only one crucial point which defines the geometry which will be used in the end...
BR
Mike