I disagree. If the amount is low enough that it only incentivises people that are desperate, you are at arms length hiring people at poverty wages. I agree that we seem to have such low expectations of our society, that wanting something better than that seems fanciful and foolish.
Wages become a market question. The more their worth the more people start looking for a limited supply. Suppose you could pick up a can every 6 seconds (including time to collect deposit) that’s 600 cans per hour at even 5c per can people would make 30$/hour which is solid pay. Except at that value people would go out if they could pickup a can every 12 seconds and make 15$/hour, down to whatever wages still motivate homeless people.
At a higher value say 25c/can picking up 1 can per minute is 15$/hour so again people would go out even if they weren’t collecting very many cans. Higher deposits should result in people doing a better job even if their not paid more.
That's basically the same reason why Uber can't give their drivers a raise, even if they wanted to. Unless they were barring new would-be drivers from joining.
Of course, that also means that they can't cut drivers' pay easily either. Especially with competition from eg Lyft.