No one who downvoted this is a serious reader. I would much rather jettison a bad book or movie than waste the one life I have on material that doesn’t make my life better in some way.
I think it may be being down voted as it can he read as saying stop reading entirely rather than just stop reading a particular book, ie an attack on reading as an activity. Doubt the comment was meant that way though and I agree with you, dropping a particular book if it's not rewarding is something I do although I do still struggle with myself when doing so.