Comment # 3 on bug 1188915 from Antonio Feijoo

Although this behavior seems wrong, after reading the dracut documentation
(https://mirrors.edge.kernel.org/pub/linux/utils/boot/dracut/dracut.html#dracutconf5),
it's done on purpose.

-->
dracut.conf is loaded during the initialisation phase of dracut. Command line
parameter will override any values set here.

*.conf files are read from /usr/lib/dracut/dracut.conf.d and
/etc/dracut.conf.d. Files with the same name in /etc/dracut.conf.d will replace
files in /usr/lib/dracut/dracut.conf.d. The files are then read in
alphanumerical order and will override parameters set in /etc/dracut.conf. 
--<

So, I think it will not be easy to convince upstream to change this order...