Board Thread:Plants vs. Zombies 2/@comment-26846900-20190131125213/@comment-24275721-20190208145736

Can someone explain this to me? In Ail-mint's upgrade table, the poison duration decreases with each upgrade. Yes, I know the damage increases as well but if the duration decreases instead of staying same or increasing, how is that an upgrade? Seems more like a downgrade to me for that specific stat.