I dont think anyone is advocating plowing the Walmart parking lot with it. It does have limitations. That doesnt mean its not a "plow truck", all it means is that it should be used for a different purpose than a big truck. It doesnt have as much power or weight as a big truck but it can get into more places. There will be increase wear and required maintenance but thats the case with any truck. The good thing about the Jeep is its alot less expensive and easier to maintain than a 3/4 or 1 ton.
Hey wait, "different purpose, power, weight, size, tight places.... hmmm, sounds alot like the "Hummer vs Jeep, which one is better" threads that always seem to pop up and the answer is always the same, depends on how its used.
Would you consider a Willys, CJ, TJ or YJ bad choices for plowing? they are all roughly the same weight as an XJ, they have the same steering and front axle strength, roughly the same drivetrain strength. Is it just the unibody construction that bothers you? That bothers me a little also but the fact is, as far as side or twisting loads go, its probably stronger than the frame of an early CJ before they boxed the frame.