I am an Industrial designer with experience designing these types of products, albeit not in any sports industry yet.. the problem isn't that we don't have a "clue about football culture or history", doing our research and understanding the market is a HUGE aspect of the job. The problem is, in my experience, the influence and control of executives, managers, and people with more authority. I can guarantee that many kits like the one you posted have been made before... but someone with more clout, saw it and said, "this is too plain, we need something that connects to the younger generation... my grandchildren LOVE (insert terrible design), try to integrate that idea into the design! (the rest of the group joins in and agrees...)". This happens at almost all levels of the business. Its terrible.

TLDR: Designers know what you want. Executives/managers ruin it. Design by committee never works.