The Pseudodragon's Sting attack says:
the target must succeed on a DC 11 Constitution saving throw or become poisoned for 1 hour.
It's worth noting that no additional save is permitted.
If the saving throw fails by 5 or more, the target falls unconscious for the same duration.
There is no mention of being Poisoned and indeed, it seems like they indicate this as a different effect that just runs for the same duration.
Being unconscious in combat can definitely be bad, but I think there are a lot of instances where being Poisoned for an hour with no additional save is worse.
Is this interpretation correct, or are you also Poisoned for 1 hour if you fail the save by 5 or more?
Compare this to the language used by the Ghost's Horrifying Visage:
...succeed on a DC 13 Wisdom saving throw or be frightened for 1 minute. If the save fails by 5 or more, the target also ages 1d4 × 10 years.
And the drow's poisoned crossbow:
...the target must succeed on a DC 13 Constitution saving throw or be poisoned for 1 hour. If the saving throw fails by 5 or more, the target is also unconscious while poisoned in this way.
The exclusion of any language linking the latter effect to the former makes it seem like Pseudodragons follow slightly different rules.