Only time I can think of this situation is either a new room mate in a shared house, or you are at a very crowded laundromat with all machines used.

In a room mate situation - I'd put his shit on top of the washer if he left it for more than an hour or two and I needed to do my own, as a lesson this is a shared facility and you shouldn't expect others to wait for you. Not gunna put it in the dryer for them because I have no desire to do their job.

If it was a crowded laundromat with no washers free- I'd unload their shit and toss it on the floor after 20 minute (maybe) as a lesson this is a shared facility and you shouldn't expect others to wait for you. Not gunna put that shit in a dryer because I have no desire to do their job for them.