I am hoping a member of the WP team can explain why this is set up this way.
I do not use child categories at all, but in order to test a theme I imported the WP test data. As many might know, there are child categories in this test data.
When using the categories widget built into WP child categories are simply surrounded by
like all of the rest of the category items. However, when using wp_list_categories() in a sidebar child categories are set up as an unordered list that looks like this.
<ul class="children"> <li class="cat-item"></li> </ul>
The first inconvenience is that this class uses the same name as the class used in the threaded comments. If you want to style what a nested comment level looks like you use .children. So what you apply to this style could easily effect both of the comments and the categories. (Yes this can be worked around by targeting your css, which is why I simply called it an inconvenience.
Then a second inconvenience is that now we have to write extra css to handle the ul ul and li li that effects the child category. Which can also be worked around. But what if you are using em font sizes, there is a good chance that the child category will have a smaller font size rendered than the other category items.
Why aren't child categories simply surrouned by
<li></li> and given a unique class name in case someone does want to style it differently?
Could someone informed please tell me if these are over sights, or done for specific reasons? If so what are the reasons, and why does the category widget display differently than the wp_list_categories() function?
Looking over the wp_list_categoires() function is in wp-includes/category-template.php it doesn't seem like a hard thing to change. Will this be changed in any future WP releases?