it just puts more time for when you actually need to visually upgrade the skin you just made it just seems like a lot of extra added time that could be better put after they fix the issues with oudated champs no need to give the walking egg plant 
a warden skin when you should give him one after you fix his base rig
cough 
cough
As Riot has said many times, different teams work on different things. The team who works on skins, probably doesn't work on visual updates.
If I'm not mistaken, the skins themselves are low enough quality skins that it would be a good gain in the short term for the champion to get the skin without their updates affecting their ability to get their visiual update. Same thing happened with Safecracker Evelynn, where she needs a visual upgrade, but the skin was a low enough quality skin that Riot could justify creating the skin without it needing improvement from her base model, and the warden skin for Jax is basically the same thing in terms of quality.
