To some extent you are right. But on the other hand the product is rarely used at the extreme temperatures...BUT WITH THAT SAID...the military customer and military user place a much higher value on functionality at a critical moment @ -35C, than they do on the need to cart a second charged battery pack around with them. Secondly consider that the heating takes place in a very localized place just under the LCD glass and then only up to 10C or 5C. It takes a surprising small duty cycle to do the job. In both cases where I had first hand experience with this the LCD is enclosed inside a sealed box and has a special EMI filter glass in front of the LCD module. This has the effect of making the module be somewhat insulated from the external environment.

Michael Karas