Depending on how you mess with the system menu, Priiloader can become unusable since it installs to the system menu. If, for example, you install a system menu in conjunction with an IOS stub for that system menu, Priiloader gets erased because you've overwritten the system menu, the system menu can't boot, and you can't save your Wii without bootmii as boot2.
By default, bootmii as boot2 is set to launch automatically at boot with the proper easy-to-obtain files on your SD card. The reset button is irrelevant.