Fast food is defined by not having table service and being more intended for carryout than dine in eating. So either you’re asking for a system that relies on fast food restaurants to provide reusable equipment and that demands diners come back just to return it, or you’re gonna have to find another business model to support. It’s not about blame, that’s just how the entire business model works, and if a person wants not to support it, they have to make individual decisions not to do so…

You chose a seemingly intentionally rude way to respond. There’s a whole lot of ways to decline something, and it’s just as easy to be polite as not. “Sorry, I don’t have time,” even just “sorry” and keep walking are great options. Or you can choose to make someone feel bad just for asking/needing help with something. Not sure why you’d choose to make a stranger feel bad, but I guess that’s up to you.

And btw, the way you are responding to comments makes clear that, rather than genuinely asking this question, you are just looking for people to tell you it was ok to be rude.