Maybe because they're...not lasers?
Although I couldn't tell you without consulting a manual, the lasers used in the games might not be a true laser. Perhaps it's just a laser-amplified particle beam, or a laser decelerated (by what means, I couldn't tell you. How do they decelerate Tachyon beams?).
Since I'm not an expert on Wing Commander, only a slightly more than casual fan, all I can do is give you an example from what I DO know: Know those "lasers" in Star Wars? Those aren't lasers. Those are actually an energy beam given off when a laser strikes a certain type of gas. The result is more powerful than a laser, with the additional bonus of being a "tracer bullet" or an illuminated beam so you can track your stream of fire. Maybe that's what the WC lasers are, too.