As SLF, I'm surpised that Cabin Crew have to clean the cabin but agree with posters that say 'we sometimes have to do the dirty work to get the job done' It happens in all walks of life. So long as we don't find cleaners as cabin crew!
What might help is if each seat-back pocket contained a bag specifically for rubbish. I now put all my discarded napkins, plastic bags, cups etc into the sickbag & leave it on the seat. It must look ominous , but its better than throwing the rubbish on the floor. I did suggest this on a JMC feed-back form, but heard nothing. So if anyone wants to take up the suggestion, there's no copyright on it.