This maybe seems trollish or silly, but in all seriousness, if your sensors aren't good enough, first rule out improving the sensors before you try to compensate with the system.
So basically, this is human error, but exacerbated by a lack of training in cruise problems and poor feedback from the controls when the copilots gave conflicting commands.
189 people died.
(Also note the failure to react properly to the stall warnings. This comes up again and again.)
(Of course, in a couple of decades we'll probably have a much more accurate external method of finding out speed/airspeed.)
Maybe we'll just have really accurate GPS and beam external local instantaneous wind-speed measurements to the plane.
At least every one I've seen is labeled "heated probe" or the like which probably wouldn't be necessary if they had to be manually de-iced.