Got reject from App store Guideline 4.2 - Design - Minimum Functionality

Hi, guy, i try to make an app for my WordPress blog

this app fetch post from WordPress API

and I got app store to reject for reason

We found that the usefulness of your app is limited because it seems to be intended for a small, or niche, set of users.

this app is published on Playstore
I don’t know why isn’t pass I thought if not have an internet connection this app is useless
I thought will try to add offline content
thank for advice