The reason why people keep matches in the bathroom is to light the match to briefly mask unpleasant odors in the bathroom.
The burning sulfur of the match head produces sulfur dioxide, which is a pungent gas which can temporarily neutralize or mask odors of feces and urine.
The match lighting doesn't eliminate the odor causing compounds but instead temporarily masks the odor.
The reason why matches get rid of stink is because the match masks the odor and stink with it's strong sulfurous smell of the match's ignition.
The burning sulfur of the match creates a pungent odor which overpowers the other smells and stink in the room, which creates a temporary illusion of freshness to the air.
The phosphorous in the match when lit registers in your brain as being a more urgent smell to pay attention to, so that you smell the match sulfur more than the stink.
When you strike a match, the head of the match ignites and produces sulfur dioxide and other byproducts.
The sulfur dioxide gas has a strong and pungent odor which is easily noticeable.
The powerful sulfur smell of the match when lit, overwhelms the olfactory receptors in your nose and makes it difficult for you to perceive other, less potent odors, including the original stink.
The masking of the stink or odor from a match is only temporary and once the sulfur smell dissipates, the original stink or odor can become noticeable again.