I'll bite on the ugly idea. Yes Mexico has more than it's share of litter,straight pipes into streams & buildings that would look better were they painted, too many utility wires and so on. My wife is always bothered by the trash lying about. I see it too but it doesn't keep me from the many good aspects of Mexico & it's people.
They are actually starting to pick up the trash down there last few years!
Guess who picks up the trash in my KY home? One guess is all you get!
Main diffs I see over time are roads & signs and some buildings & of course in touristy areas like Play del Carmen where the influx of money has changed things in a huge way-not all for the better IMO. Wasn't it 1974 when Mexican govmt. started the Cancun thing? Not much there before then. I can remember standing in line as recently as late 1980's to use THE! phone in Playa. Now they have big macs & traffic jams...
watch out what you wish for huh...
"If I had my life to live over,I'd dare to make more mistakes next time...I'd relax,I'd limber up.I'd be sillier than this trip, take fewer things seriously, I would take more chances... take more trips...climb more mountains...swim more rivers...eat more ice cream." Jorge Luis Borges, at age 85