When one selects the Tags menu option at the top of the page, it appears that the tags are presented in the order they are used most. This makes it onerous to find a given tag. One needs to sequentially read through the list to try to find a tag, and there are multiple pages.
Similarly, when one goes to assign a tag to a post, the tags presented in the drop-down list are in some unknown order.
Presenting tags in an alphabetic manner is much more common and easier to use.