I strongly disagree.
And, for the record, I don’t leave keys. But I support the right for any player to leave a group at any time.
m+ was not designed for the pug experience, and it should not be ruined, or we should not walk around with scarlet letters on our characters, because of the pug experience.
At the end of the day, leavers are not a problem in good groups.
build good groups.