Bug#823286: xserver-xorg-input-libinput: Significant functional regressions for touchapds vs. xserver-xorg-input-synaptics

[Laszlo KERTESZ]

I toot had this issue on a Dell Latitude laptop (Debian Testing, Mate
desktop). My custom mouse deceleration was the first issue i noticed
missing, then the touchpad clicks were gone away, then i saw that the
mouse/touchpad gui showed only mouse. I tried replicating the constant
deceleration settings but the xinput options were very limited. So i
removed the libinput diver and that was it.
Why was this functional regression done?