It's harder than it should be. There are plenty of quality coaches out there with years and years of experience who don't gain it.
One reason for this could be that they coach in a different way to the standard FA robot. I've coached 7 years and I am due to be assessed Level 2 but I don't have high hopes, not because of my ability, but because of my style.
My brother was assessed a couple of months ago and failed - despite coaching for 8 years....so he's only qualified to the same level as Joe Bloggs' dad who has done the level 1 gimme.