Gaurded Switches keep Junior out of trouble
There are gaurded switches in the flight deck to keep the first officer (Junior) out of harms way and / or to prevent inadvertant operation off said switch. Most are involving emergency operations or systems not used in routine flight aspects.
Of course there's also the reason concerning the curiousity or engineering safe gaurds needed for the safety of some flight crews. Much like the reason Shorts SD3-60's have rubber blades in the flight crew auxiliary fans. There would be an awful lot of digits missing in flight decks today without the rubber blades