Because then I need to make a fourth skin for every weapon, or settle for different weapons having different skin counts, neither of which I would particularly like to do.
My own preferences aside, three is also a good number of skins if rarities are implemented - one for each tier.
Speaking of which…
I’ve added a series of polls to another topic (there’s quite a good number, and I didn’t want to clutter the scroll length of this topic. They don’t seem to want to go in spoiler tags…).
I’m trying to gauge the relative popularity of the current skins.
You can vote here.