ouch... but anyway, that's only 1/216 of the time. You'll on average move 10-11 inches. That makes the bright lance around 48'' assault. Which is very useful. More often, my death jesters will be just out of range of heavy weapons, and as they move that extra 12'' to get into range, they're lascannoned...
Also, you're never going to be so close that the extra possible 12'' is going to make a difference, unless you plan to come within 18'' (Bad idea)
It also comes in handy if you're being chased down, since you have a fairly good chance of outrunning jetbikes and the like. Infantry moves slowly, so while it has less of a need, it's still very useful.