Vector Bundle Rejected please help someone

Tried to sell on GraphicRiver this bundle/set of items (https://www.behance.net/gallery/45297655/School-Supply-Vector-Pack)
This is the only thing they said "submission is too far off the standards we require"
Is this really that bad? Do you have any suggestion how to improve? And what to improve.

First of all - is it your item? Second - is it well organized etc.
I like colors of those supplies, and though I don’t know where I would use them, I kinda like them.

Yes it is 100% completely mine and made from scratch (from mine imagination). And what do you mean by well organized? Is it important? I mean you can see how organized it is in my portfolio:(https://www.behance.net/gallery/45297655/School-Supply-Vector-Pack)
I simply cannot believe that my design is that bad and could not be sold as a vector pack.

I don’t mean the presentation, because it is alright. I mean after someone dowloands the file, is it well organized and everything is easy to navigate through?
The rejection itself sometimes isn’t because the file is bad itself, but because there is no demand on the market for this at the moment.