This looks like an awesome feature that could really breath a new level of customization and character building into the game...
I really want your perspective on this, how exactly? If it were anything to do with customization or character building we would be forging our own weapons, not handed things that already exist within the lore on a convenient silver platter.
The average player who doesn't even bother to transmog will look identical, even less variety than before this system. And people who do transmog will be limited in what weapons they can use based on their spec. As a Mage I could use Wands, Swords, Daggers, Off-hands, Staves... Now I get one, based on my spec entirely.
People keep complaining about weapon RNG, but what about gear collecting in this game isn't RNG? Just because it has the biggest stat impact, where do we draw the line? How long until all gear is removed? You run a dungeon to fill a bar that makes your stats grow half a percent and you buy skins to throw over top of it all so you don't look like the 95% of people who are going to think the base sets look "cool enough".
36 base weapon models, ~180 derivative models total with alpha channeled textures for easy re-colouring. With scaling stats. WoD had 1,745 different weapons. Granted a ton of them were recolor or straight up re-used models. But without having a readily available number straight from the game, I'm willing to bet it had 2-3 times as many unique models. They say there are options for making your artifact look unique, but really... If you PvP you'll probably want to use that version to show it off. If you raid you'll use that one instead. The colors are likely going to be gated to a tier, rating, or something else incremental meaning you'll be encouraged to use the highest available one and fit your gear transmog to match.
The biggest complaint I forsee is everyone looking identical, especially if you have a room full of your class in the garrison v2. There are going to be people praising blizzard for "having the forsight to offer special skins in promotions and for sale to combat this problem"