So I am curious.... Has Disney ACTUALLY gotten dirtier, or have we just become more aware because of technology. Note this is rhetorical. I do not think this is something we can ever 100% answer. Even if someone says in their experience, that is still just one person's experience. Unless we have a true statistical study of thousands, and even then you are relying on the "green grass of memories past". I question anyone who says in their experience how much they really noticed and would remember an overflowing trash can when then were 10 years old.
This is just one person's experience. Although my experience started not too long after WDW opened and I return almost yearly.
I don't remember cleanliness being an issue at Disney.
Does that mean there has never been an overflowing waste basket? No.
Does that mean there's never been spilled popcorn? No.
Does that mean an ice cream was never dropped? No.
All of those things happen and any one of us can run into a situation at any point in time. Heck, I'm positive I caused those a bunch of times. Where do I go for the nearest napkins? By the time I get back a lot of times it's cleaned up anyway.
But to your point, in the past if that mess was cleaned up within let's 5 min, heck 15 min. How many people would see it? How many people would report it? Now let's say it's 5 min. How many people could take a picture of it? Even if it's 5 people, it's out there. Those 5 pictures add to the 5 from a month ago to make 10 instances, etc etc.