The motivation for these types of speakers is the simple fact that it is impossible to build a speaker cabinet that DOESN'T resonate. The idea is, if you cannot damp all resonances (and you can't) you might as well make it work for you. Note that I am not championing the design, but that's the rationale (and it's true you just can't make a dead cabinet).
Consider that one can hear a train from tens of miles away by putting ones' ear to the track. Does the hundreds of tons of steel in the track "damp" that acoustic energy? No. One can hear horses approaches from miles away by putting an ear to the ground - the mass of the earth slips my mind at the moment but you get the idea.
The reason open baffles can sound so good (for so cheap) is that they sidestep the cabinet resonance/backwave dampening problems altogether. The 'resonant cabinet' school of thought is a variant, perhaps between the OB & closed-cabinet schools.
