You have to realize that PC supplies might work outside, but some of us in less than frinedly climates may need to look at alternate means. For example, we went from near zero, up to 30 and got 6" of slushy snow, back down to near zero, up to above freezing so everything got soaked, then it froze again. Wihle I might be able to build an enclosure to reasonably protect a PC supply from that...the enclosure may land up costing more than just getting pure industiral 12V supply. Therefore I'm just getting the parts.
Secondarily. I am spending thousands on these little buggers..what is another $10. <fp. What is that, like another 30 minutes on the couch?