That's some feedback that can be made for it, as we don't even know if this is the final product (I'd assume it's not). However, I don't think it's a literal waste of time if it's shorter than most trips people would take with a flight path. Plus, this is just going to a specific zone, not travel w/i the zone, so the frequency of this travel method is likely not going to happen more often than normal FP travel that would happen inside a zone itself.
I'm fairly certain the intent behind this mechanism is to give a sense of distance between these realms and traveling a long distance at 'fast speeds', versus instant portals everywhere. From a technical standpoint as it is on the alpha, it's the same as flying between the same flight path where the scenery on live would still be the same every trip. I guess the most analogous scenario would be flying directly between Hellfire Peninsula and Netherstorm in TBC through the Twisting Nether... and instead of flying through a purple haze with some celestial bodies, you're flying through a light-bending show. While they accomplish the exact same travel, the Shadowlands one is meant to instill a sense of speed and large distance travel.