The only good reason for a leather glove is if you're hand starting the engine, which isn't a good idea anyway. Try setting a needle valve with a heavy glove on your hand. Just the thickness of the glove will most likely cause prop contact where a bare hand would not have. (Not true for remote needle valves.)

A glove will also give you a sense of safety and confidence, so the first time you DO go to remove the glow igniter without the glove (on a hot summer's day) you'll get bit anyway. [:'(]

Better to establish a set of procedures that you follow the same way, every time, when working around the engine; then try to concentrate whenever the engine's running. I have found that using large, exaggerated movements helps me stay alert while working around that meat grinder.
Dennis-