denominal adjectival suffices

What is it about words changing their lexical category (or part-of-speech-hood), especially by way of zero morphology, that lights a fire under the tails of word snoots and their ilk? Somebody was just blogging about the use of crater as a verb (as in something the world economy just did), and just generally pissing and moaning about language change and word use. The first thing I thought about was Greek κρατηρ ‘mixing bowl’, which in turn led to a reverie on the sacro catino in the Duomo di San Lorenzo in Genova, one of four or so candidates for the Holy Grail. But when my mind returned to linguistics, I marveled how the participial suffix -ed in English could be applied to nouns to create adjectives. (What is it about adjectives and verbs and their transgressive relationship with one another?) For example, cratered, bearded, horned, etc. Then I realized something similar happens in Latin: aurītus ‘long-eared’ < auris ‘ear’, barbātus ‘bearded’ < barba ‘beard’. This was not the first time I had wondered about verbal suffixes pulling double duty with nouns and adjectives: cf. -l- and -n-.