The Alps switch design prevented tactile and clicky switches from having an LED. The LED in SKCL (complicated linear¹) green/brown/yellow/grey consumes the space where the click leaf or tactile leaf would go. The switch is a cube and is pretty packed inside.
Someone has, however, made a fully backlit 60%-ish aluminium keyboard with Matias switches, whose transparent shells allow the switches to be lit from below the PCB.
Tactile and clicky Alps-style backlit keyboards are now possible, but only with Matias switches. If you're a linear fan, you can use genuine linear Alps switches.
¹ (note that it's just a coincidence that the family part code has "CL" in it — nobody knows what CM and CL actually stand for. SK means "single key" apparently)