This is well known (check any discussions about item quality). It can also be noted that you can't craft clothing of higher quality than decent (it's capped), but you can find higher quality clothing in villages.
The logic for clothing and bowls at the least, is that once the item it's fully functional with no flaws, it just doesn't get better without embellishments the character cannot engage in. In the case of bowls it could be intricate carving, while in the case of clothes it's because well tailored clothing takes a lot of time to make, and the current UrW model for tasks generally doesn't allow for interruptions (there are some exceptions, with more to come in the future), so you just can't spend 40 hours one making a masterful bear skin cloak with all the bazillion smal,l quality, stitches and whatnot required.