I think it was Imagine who said it before, but it was removed purposely. The exp shop is supposed to be somewhat of a replacement for enchanting tables, since they are disabled. Mending is not obtainable through an enchanting table, hence why it is not there. It is a treasure enchant, it's supposed to be somewhat difficult to find.

 

I agree fully, it was originally added to the expshop because:

- EXP Sink in buying the enchantment
- Allows less exp into economy
- Allows players to not be wholly dependent on others for repairs

Frankly I don't see any reason for it to have been removed, there's literally no benefits in it being removed.

 

+1

 

+1

 

In light of the support of having mending in the shop, as well as it's uses as an exp sink, I've readded it. It is in the same category as Unbreaking since it can be applied to every tool.