I'm new to the Genesis framework and am confused about it's child-themes. The Genesis theme itself has it's own theme stylesheet but you're required to install a child-them to use Genesis. The child-themes I've seen (ex. Genesis Sample http://demo.studiopress.com/genesis-sample/) totally recreate the stylesheet. That seems pointless to me—can someone tell me what I missing? Is there a best-practice way to import the parent style sheet and customize the child styles off of it?
If your child theme relied on the Genesis style sheet, then, when Genesis changes its style.css (as it did for 2.3.0 and it may for future versions), suddenly an update to Genesis (which may be applied automatically depending on your setup) will break the look of your site.
Another reason, is that including genesis/style.css, and your-child-theme/style.css is an extra HTTP request (with subsequent overhead) which may impact performance slightly, if not on HTTP/2.