I do understand how it works, I just don't like it. Sure, if all I did was use the distro kernels and let it run the scripts it would mostly work. In some distros I still have to correct what it adds for Windows partitions though... I really don't need it adding stanzas for partitions that don't even have a Windows OS on them. Mint 16's grub autoconfig actually got all that stuff right. It adds too much stupidity to my custom kernel stanzas though, when it just needs to be simple.
I build my own kernels (configured my way), and if I let that stuff run I would have to go and edit the stanzas because it adds lines and parameters I don't want. I could correct all this but I don't believe in manipulating a bunch of scripts just to get something to automatically do what I can in 2 seconds with a text editor.
Even if it does get it right, I would still have to go and check grub.cfg to make sure.