Well it actually IS a torque converter (as any cvt really)
since it'll convert high rpms into low rpms and low torque into higher torque internally.
It's just a matter of viewing angle.
Since there is little to no overdrive (most none, asymmetric with max 10% OD),
it can't actually add more speed (at least not on it's own)
and thus it's main purpose is indeed to add torque when needed (hence the name).
Names are just conventions..
a motorbike technically is an automobile (autonomous vehicle technically)
still you wouldn't want to call it that, would you?
On the other hand, calling a car autonomous (literally) is still a bit of a stretch today.
So as long as we all agree upon what an automobile is, we can call it that and still know.
it's not a motorbike and it does need a driver (with very few exceptions

)
'sid