or someone that is realy desperate. normal people in desperate situations can do crasy things...
allso, look at the cost vs effect. you can basicly match a person useing low level wired and mid level boosted with one dose of kamakazie, and for someone on the street it will be mutch easyer to get hold of then hell. when the down and adddiction comes well lets deal with it. it may even be interesting from a roleplay situation to play a addict

and it uses a inhaler even. no messing with needles or anything like that. and with a instant effect it will be something for the gangers by the numbers.
and its a classic cyberpunk theme, drugs are everywhere, its replaceing alcohol as the party starter of choice. rember that in the 70-80 people where snorting and smokeing all kinds of stuff and vietnam vets where morphine addicts many times as it was the most common anastetic in use in that warzone (1 or more while getting trasported to the chopper, 1 or more on the flight, god knows how many while in surgery and while recovering)...
as for speed in the matrix, no drug or magic can help as its a purely mental system. drugs, cyber and magic all enhance your physical reaction time. the matrix is all about how quick your on the uptake, kinda like a drektossing contest among friends...