With all due respect, clearly that's not the case, at least given the amount of negative reviews on VB and the most common complaint being the wait times. And there is no way, the average standby wait at Disney exceeds 3-4 hours like some of the slides at VB seem to.
Look, Fastpass is by no means perfect. Far from it. However, right out of the gate, it's got TapuTapu beat simply because you're guaranteed at least 3 rides. There are many people not getting that at VB. Granted, it's kind of apples and oranges as one is a water park (regardless of the Universal spin). However, for a more accurate comparison, look at the world's most visited water park, Typhoon Lagoon and ask anyone if they ever leave the park without being able to ride a single slide.
The bottom line, to me anyways, is yes the systems are completely different, but the end result should allow for the guest to enjoy most, if not all, of the park's attractions. At one, you can. At the other, most people anyways, can't. TapuTapu, unless it allows for you to tap in but go ride another slide, is all smoke and mirrors.