I guess some virtual pianos have repedalling/hald-pedalling switch just for CPU/disk performance reason.

Even impossible when play at extreme high tempo.

Maybe better don't play with with extreme high tempo. Better listen to the beauties of the music you play. You may need time for it.....

:-)

Many virtual pianos have repedalling, Pianoteq just do it best. But WHY anybody even need to disable it?

Many virtual pianos have the feature indeed. However, a switch is also there. It's rather helpful if you turn it off when play pieces at high tempo. You can catch notes easily and mute the sound of previous chord just by lifting your foot and pressing down quickly. However, when you play on a real piano, it's quite difficult to keep a clean sound while catching all the notes which shoud be sustained. Sure, I admit that my pedalling skill is not very good:-). Even impossible when play at extreme high tempo. So It's an "advantage" of virtual piano without repedalling(just for people like me?), though repedalling is useful when play detailed music.