I lived in France for 10 years, virtually nobody picked up waste from their pets. Just wasn't a cultural norm. Not necessarily that different in Italy or Spain as well.
I remember noticing the same in Marseille about 10 years ago, but Paris for example was already quite different back then.
Now I live in Madrid and not picking up after your dog is very much frowned upon, and you see very little pet waste in the streets.
To be fair, the French men also routinely pee on buildings and alleys in public. Your observations of Spain puzzle me though. I always found the Spanish to be exceptionally festidious people with remarkably clean streets.