Well, Fedora developers by definition count as power-users. What I do is to set the GRUB delay to zero on testing VMs where it does matter. Anyway, for testing and developing on VMs it is better to not boot the system from scratch, but start from a snapshot of an already-booted system.
Well, as I see it, I am probably one of the last Fedora users, who also use Fedora on servers. For me, it really matters whether I would be able to get into GRUB every time _I_ want, independent on whether the system _thinks_ the last boot finished correctly. Especially on those pesky HP ProLiants DL125, which take three+ minutes to go through various BIOS stages. The advantage of being able to stop the GRUB when I want instead going through another system reboot is bigger than saving 5 seconds out of about 200 in the ordinary system boot.