I have a routine. I clear my front page often - see if I want to watch things immediately or later when I have more time.
I make EXTENSIVE use of the watch later feature with a reasonable degree of faith that it will be there for me to watch when I have the time. A design decision which tricks me into deleting things from the list violates that trust and offends my inner OCD demon that wants to clear the front page.
One button - one purpose. That is all I am asking.