sue you can hard wire it in, but why? You would need to use a whole lot more time, material and expense, compared to adding a box and receptacle to use the factory cord. Once you jump up a notch, past the $10 crap "shop lights", fixtures no longer come with cords, and they are designed to be hard wired either from the back, or ends of the metal housing.
Are you suggesting those Costco LED ones are "crap?" If so, what's sub-standard about them?
As for why hard-wire, it's obviously better than using outlets for a permanent installation (and I don't see why it'd be any more expensive either).
I didn't mention it explicitly before because I didn't want to hijack the thread, but I got a bunch of these for my basement (which was lit by exactly two single bare bulbs for an 800 ft
2 space with almost no windows... it has a couple more, but when the house was rewired 15 years ago the wiring to them was cut and not replaced). The Costco LEDs are currently jury-rigged to a power strip hanging off the single, solitary receptacle, but I'd like to wire them up to the switch by the door (with romex running properly through holes drilled in the joists, rather than extension cords draped across the top of the ducts and pipes).
I guess having outlets in the ceiling wouldn't be
that weird for a basement, and might even be convenient for things like powering a table saw in the middle of the space. Still, it just doesn't seem right to me.