hi I can’t say that this is really bad but u have definitely things to improve , according to me, as well. The first thing that immediately come to my mind is that there is a disconnection between some parts of the design. The black color is coming out of the blue and only present in the text part. The balance between elements and white space is a bit looking anarchical in a way , elements are not always positioned in an optimal way to give some elements the right environment to shine, get the right exposure, impact and attention. Look for instance the block of text in the information side is very close from the end “yellow peaks” and this is somewhat choking a bit if u ask me … this positioning is also creating an overall misbalance that ends up making people feel like there is a misalignment, like with the logo in the data side … the background is not super worked out otherwise and finally apart from color peaks “around the card” there is rather limited graphic design out there. I would this suggest that u push the envelope a bit in terms of graphic design. This would help to value the content of the main zip file while, right now , this is a bit limited , in my opinion, so that u can ultimately get more extra value being brought to the table and the commercial potential of the card will go up as the originality by the way. The contents are a bit somehow some way choking a bit , too. I would suggest that u try to work on a really professional looking logo that will take your item to the next level rather than contribute to flatten it, like the “logo” that u have at this stage. I am conscious that this is for reviewing matters but all details matter … Pls also consider paying attention to the preview even more there are some mistypings there and this is do not look great to have any if u know what I mean
Can anyone explain, briefly and clearly?
who doesn’t beat around the bush?
what is this meaning? u want a summary in your case also? 
(this looks trendy as of late lol kidding bit , peace) or u want me to tell u this is perfect and unfair this was rejected? I do not get it … I just try to help , I know that criticism, especially when there is a good deal of it can be hard to swallow so to speak, but my goal is not to “thrash” but to help. Indeed, if u keep on the surface u will never get to the next level, and having u getting to the next level is what I am trying to make u do? do u understand?
1- make sure sure that there is more homogeneity between parts
2- forget about black color text or introduce some black somehow somewhere
3- anarchical organization
4- white spaces and busy parts are unequal
5- yellow peaks disturb the text elements as such
6- lack breathing around texts
7- positioning of some elements creates misbalance
8- too simple background
9- invest time to create professional logo
As a composer and no graphics specialist I can only say, that this design doesn’t meet my expectations. It looks somehow uninspired and very simple. There is no exclusivity in my eyes. But that’s only an impression and does not help you to improve in detail.
If I read some long explanations here, why a design was maybe rejected, its really hard to understand. Maybe its hard to describe. Or…the more possible reason…its because I’m not a graphics designer.
But its interesting to read, how many little details must be considered to get a good design.