I, and likely many others, finished the achievement Fashion Forward long ago; have 1,000 unique skins in your wardrobe. I enjoyed adding to this one (the little unlock popup is always satisfying) as well as lording over my friend who is much more fashion-obsessed but has fewer than me. At the very least, it was interesting to have a numeric counter of how many skins I had, but it stops counting at a thousand. I would be happy to have more tiers to pursue, and for achievement hunters I would imagine it would at least slightly spur skin acquisition, which is a good thing for Anet.
A tiny suggestion but there was nowhere else to put it, so now it’s out there.