There is nothing proprietary to the cabinet, all ports are standard and it is quite simple to install a gaming console iinside of the cabinet to then use it with the monitor and arcade sticks.
The arcade sticks and buttons are of American make and so are not seen by most hobbyists as professional since they are less precise when compared to Japanese or Korean parts. While the controller can be modded this may be difficult to do for the layman.
While some may not mind, there are zero games preinstalled on the machine meaning one will have to know where to get the ROMs and which ones are compatible with what emulators.