They can be polarizing. Some hate them, some are indifferent, others appreciate them. To the city they're a nuisance, because they take recycling money out of the pocket of the municipality. To some residents they're considered a threat or an annoyance, afraid of theft or annoyed by noise in the middle of the night.
Personally, I appreciate these people. I will collect my bottles and leave them out on a discarded table that sits in an alley on the route of the bottle collecter currently informally serving my neighbourhood. I live in a downtown area known as a party spot, so he does reduce a fair amount of litter by collecting the empties discarded just about everywhere.
It's reassuring that somebody sober is out on the streets and alleys at night. If somebody passes out or is otherwise in trouble, he may be the only person that would discover them.