Google Play rejected our app because of the youtube API

My friends and I made a (completely free, no ads even) app to teach languages through songs. So in the main activity screen, we put a music video of the song by using the Youtube API, along with a link to this site called Xiami which is like the Chinese version of songster because our songs are East Asian Languages. When we tried to upload it to the playstore, they sent us an email:

REASON FOR REJECTION:Violation of section 4.4 of the Developer Distribution >Agreement.

After a regular review, we have determined that your app downloads, monetizes, or otherwise accesses YouTube videos in violation of the YouTube Terms of Service or YouTube API Terms of Service. Accessing content, a product, or service in an unauthorized manner is a violation of the Developer Distribution Agreement, and is not allowed on Google Play.

All submission rejections are tracked. Repeated rejections due to policy violations will result in app suspension, at which point this app will count as a strike against the good standing of your developer account and no longer be available on Google Play.

It’s quite vague what exactly we violated. I read through the Youtube TnC and couldn’t seem to find what we did wrong. Could anyone point us in the right direction and what we need to do to get it approved? Some other apps like Shazam seem to use the YouTube player. Thanks!

Google is such a stupid bot. If they don’t want the developer to use their api, they should not create their api.