"Soft" keyboards on a touchscreen have a number of disadvantages, the biggest for me is that they take up a large part of the screen. I could use the terminal or edit source code just fine on my phone's screen, but only if at least 40% of it wasn't taken up by a keyboard. Secondly, I think you're underestimating the number of "weird" sequences of characters programmers and terminal users regularly type.
Sure, a proper keyboard and a table is always better, but there are often situations where such a comfort isn't available.
This doesn't apply to devices which have slide-out keyboards or a clamshell design. The linked design is more "Blackberry-style" as far as I can tell, but those are not the devices I primarily had in mind.
This is why I pre ordered the Fxtec Pro1, a landscape slider android phone with microsd card and FM radio. Oh, and yes it does have the increasingly mythical headphone jack.
Sure, a proper keyboard and a table is always better, but there are often situations where such a comfort isn't available.