typically, they don't. :-)
reforms are the only way (or at least the primary way) one can work "within the system" for change. they (reforms) will almost certainly help someone, in some way, for some time. so if one's desire is to have some relief for some people in some specific area, then reforms probably seem like a good thing. and to some, no doubt they are.
unfortunately, they have proven to be 100% useless when it comes to creating the kinds of massive (revolutionary?) change i see as necessary for any world i would choose to live in.
women and black folks able to vote? gay folks able to marry? potheads able to indulge themselves (er... ourselves) legally? corporations able to legally buy elections? cops wearing cameras?
yeah, none of that really appeals to my own desires for liberation. but again, there are surely folks for whom those things really do matter, and whose lives they may see as improved as a result of those reforms.
there are a couple reasons i no longer have any interest myself in such lefty-like endeavors.
1. i really like the pressure-cooker analogy. reforms are a form of pressure release; de-escalating the intensity of (desire for) revolt by some group of people who might otherwise finally say "ya basta!" but instead are placated by some legal move that is usually largely symbolic. reforms are crumbs thrown to the masses by those with institutional power, while they eat their lavish meals at the expense of everyone else.
2. having tried to "change the world" for a good number of years, i saw the futility of that, alongside my frustration with everything around those efforts. that approach (reformism) requires a belief that it is possible to change the system from within, or at least through using the system itself. at some point i realized that not only did i no longer hold that belief, but also that i don't want to "change the system" - i want the system GONE. finally, i also realized that (like the cliche says) the only life i could really change was my own. and that became my focus. i am a much happier - and in some ways, more liberated - person as a result.