Gameplay IS hold button to attack. Tapping is just executing the same thing as holding the button. You're not getting 1:1 strikes with tapping.
It really isn't, with the directional stick you can change the effect of the attacks (for example you can jump back in the air instead of defending and then strike again with a warp attack, all without landing), also you have to manage multiple weapons in real time, magic, defense, group attacks.
There are many layers of depth in the gameplay, it's not keep attack button pressed to win.
Btw this video looks significantly improved compared to the recent 50 minutes videos at least in the PS4 version, the desert scenes are night and day compared to the Gamescom video in terms of vegetation, now it looks like it was reasonable to expect for a game with this budget/importance.
This also suggests that their ''master version'' is more like "unfinished version".
Delay was needed to finish development, not to add the fixes of the day-one patch on disc for the poor people without a internet connection