Yeah, Shockwave isn't useless, but it ain't very useful either. Its casting animation takes too long, cooldown is too long, aiming is difficult and unreliable, effect is minor - enemies who got hit are standing (and shooting) within a couple of seconds (well before you can use Shockwave or another power again), damage is neglectable etc. There is almost always a faster, more reliable and more effective way to deal with enemies.
I've tried to incorporate Shockwave into my Adept playstyle but I couldn't find a way to use it effectively. I tried it in combination with Mordin's Cryo Blast in an attempt to use Shockwave to shatter frozen enemies. It does work occasionally but most of the time you'll end up surrounded by enemies. Shockwave isn't powerful enough to sent enemies into the storm on top of the Shadow Broker vessel (would be cool if it worked). Even levels like Dantius Tower's bridge and the Collector platforms do not guarantee successful insta-kills (Pull, Throw and Slam do and are on half the cooldown).
Nevertheless a very cool video though I missed combos - Shockwave is much more effective when used on already ragdolled enemies. But half the time Shockwave doesn't hit ragdolled targets coz its impact radius is too small (Pulled enemies or those caught by Singularity are not lying on the ground - and just a couple of feet into the air will make Shockwave's effect useless).
But you got me interested Thisisme, I'll give Shockwave another go