IIRC doesn't it say that you keep your low stats? It has been awhile since I played. We just discard all your items and flip your character card over, returning to base stats, and restart you at the entrance.
Before the haunt, any effect that would lower a stat below the lowest value cannot do so and the stat stays at the lowest value. You cannot die, but yes, you're pretty weak, which can make the time after the haunt fairly deadly.
And this is exactly why we reset people. Because we found that more often than not people tend to have items and more bonuses. So resetting their character tends to still be a disadvantage to the average character. We played a few where we let the character get to the lowest stat and they tend to die really fast, which makes the game not fun for them. Feels a little more balanced, at least to me.