I would tend to agree when talking about most cars.

However, when it comes to cars like the HCH-II and the Prius (which I regard as pure exercises in "optimal minimums") small things matter a whole lot and it does not take much to upset the fine balance that makes them work well.

From my perspective, the LRR tires in these cars tend to wear faster than regular tires and it is important to ensure that even the slightest of mis-alignments does not accelerate their wear and aging. I believe that kind of preventive maintenance is cheaper in the long run and if done correctly is always money well spent.
Also, it helps to think of an alignment in terms of FE benefits as well.

Cheers;

MSantos