For english language, swipe typing coupled with autocorrect works astonishingly well. So much so that I use it regularly because of lazyness. What segment does the physical keyboard appeal to? Youngins were born and raised touching the screen, so it's archaic to them. Old timers are jaded at this point to either wait for their dream phone or buy any cheap crap. So who's the target for this 900 usd device?
I can't really say why I like typing on a physical keyboard, but not losing half of your screen to a virtual keyboard and also having access to modifier keys like shift, ctrl and alt are the top two reasons I prefer having the physical keyboard. Also it slides out so you only need to use it when it will help.