Silly as it might seem, burst DPS is a meaningful stat when we're talking about the Raider. You see, it would be completely meaningful for one-shot weapons too - if it wasn't mathematically impossible to compute. You just have to give it the meaning it has, and nothing more. You go around a corner and find an atlas down to armor being shot at by all the team: you fire - how much damage are you able to squeeze in that small time frame? Burst DPS is a better answer than sustained DPS, and the Raider having a helluva lot more burst DPS than the Piranha means that in that situation the Raider is capable of squeezing a helluva lot more damage in 
I think you're grasping at straws here. There are so many variables at play: damage-per-shot, how many shots can you get in, how fast is that Atlas going down without you... those things matter much more than BDSP. Even if it's "a better answer" than SDPS, it's still the wrong stat to look at.
If you double Raider's ROF, you're obviously doubling its BDPS, but it's only a 23% increase to its SDPS. Do you really think doubling the BDPS would have any significant benefit beyond the increase in SDPS in that Atlas situation? In a corner case it might give you the kill instead of a teammate, but you really care about such things?
Sure, BDPS may be a meaningful stat in that it does indeed contain some information, but it's not a practical or useful stat for Raider. In fact, it's only truly practical or useful for weapons that deal their damage in smaller chunks, have numerous shots per clip (5+) and take several seconds at least to empty their clips. For weapons like BW, Wraith, Valiant, Crusader and especially Raider burst DPS is just not an interesting stat. Why "especially"? Because when a divisor gets close to zero (it takes 0.3 seconds to empty the clip), the result becomes uncontrollably large. You know that.
Also, the fact that calculating BDPS for single-shot weapons involves a division by zero should already tell you that it's indeed completely, absolutely meaningless stat for them, there's no "it would be if". Look at other stats instead, like damage per shot or effective ROF, those are the things that matter.