While it is thrusting you, you can shift to stop it. He is suggesting that it should not, but I disagree too.Do you mean we don't have to shift to charge it so it's faster?
disable shift cancel.
Although this suggestion has just been made in three words, the meaning was there, and I disagree.
As a waterbender, being able to stop WaterWave when I want is extremely important, specialy, but not limited to, combat. Removing this feature would make waterbenders to be at luck's mercê. The same would happen in this suggestion also applied to firebenders' FireJet.