Nitwit Villagers can't be traded with

Nitwit Villagers can't be traded with

*What I expected to happen was...:*
They should be tradeable

*What actually happened was...:*
Not tradeable

*Steps to Reproduce:*
1. Do /summon villager ~ ~ ~

{Profession:5}

2. Try to trade with them
3. *NOT TRADEABLE*