Couldn't afford the licence fee, last I heard...
It's a fair enough thing to do, their main problem is that you can usually choose beforehand if you're going to need desert or temperate camo and pic that, but operating around the green zone you may have to flick from one to the other. There were loads of pics of our soldiers who'd dyed the dessie stuff green in huge vats of dye to make it stand out less than the issue kit...
This was the new cam system being introduced for armour and belt kit:
It's quite similar to the existing dessie stuff but with enough green in it that you look like a shrub against a desert background but a sandy patch in the green zone. They've been doing absolutely tons of trials so you'd like to think they know what they're doing The idea is that you only issue one set of bergens etc and people can wear them over whatever uniform kit is issued without having stupid colour clash when your plate carrier's desert over your temperate uniform etc.
The system is called PECOC (Personal Equipment and Common Operational Clothing) if you want to Google it a bit more easily.
Stone