This is a recent evolution of table tennis being pushed by the coaching staff in China. The hard backspin push and other types of placement shots were more common in the last decade a before, but now the newest generation of players are utilizing this flick as a way to take initiative as Beeray says. I don't really find it hard to generate a lot of lift...so I think it is a technique issue you are experiencing. For me, the hard part of the shot is really the spin judgment of the service and thus how much lift to apply. As with all upward-grazing shots, I don't find it particularly imperative that it be hit at the top of the bounce.