Pure trivial speculation while walking the dog...
How come the primary adjectival forms of (what as a rank amateur I'd guess to be) Anglo-Saxon nouns are Latin--and in addition there are Anglo-Saxon adjectival forms that are colored or metaphorical? The pattern seems systematic for some of the most common nouns: hand-manual-handy; smell-olefactory-smelly.Sometimes one Anglo-Saxon noun picks up more than one highly colored adjective in addition to the primary, colorless Latin adjective: home-domestic-homey, homely, homelike; taste-gustatory-tastey, tasteful.
Maybe it was like this: there was a good, solid homey Anglo-Saxon noun and its corresponding adjective. Over the years the adjectival form picked up color and metaphorical meanings, sometimes even to the point where the original meaning was obliterated. "Homey" didn't just mean pertaining to the home any more and "homely" didn't mean pertaining to the home at all. So those Latin adjectives, like "domestic" got pulled in to fill the gap, to be colorless adjectival forms.
Maybe it went the other way around too. The Latin adjectives, because they were initially unfamiliar, were perceived as colorless. They didn't have the color for native Anglo-Saxon speakers that they would have had for native Latin or French speakers. So when they came into the language, the freed up the original adjectival forms for other jobs.
If I had to invent a language it wouldn't have been English, with minimal grammar and maximal vocabulary, nuance and idiom to compensate for it, unsystematic and impossible to spell. I would have invented Spanish (Is Spanish authentically an "easy language" or is it just easy for native English-speakers and, presumably, speakers of Romance languages?) Good thing English is my mother tongue--I could never have learnt it.