I think people do it here, because
a) they don't know how to check the corn through the husk, because they are used to the husked corn in packages.
b) Corn is bought by weight and they see paying for the husk as being ripped off. I've actually had clerks tell me that I could go back and husk the corn so to pay a lower price. I tell them thanks, but the slight increase in price is worth the added sweetness.
That's strange to me, because here corn is sold by ear, not weight.
I don't know how regional the differences are, or just family culture. My husband and I grew up in the same state, only 100 miles from each other, but he had never seen corn in the husk until we got married. Although they lived in a more rural area, his mom always bought the prepackaged, stripped down corn; my dad grew corn in our tiny backyard in the city.
I don't think our stores have waste bins for the husks, but I haven't looked for them. I don't shuck the corn until it's done grilling.