1 - you don’t have to worry about leaving a dish
2 - you don’t have to clean it after a get together that is probably exhausting
3 - aluminum is one of the materials that is actually very recyclable, so it’s not a big deal like plastic is.
I have melted and cart ingots from thousands of dirty aluminum cans. Rinsing first is ideal of course, but all the crap floats to the top of the molten metal as slag and you can scoop it off to discard.