Maybe I'm not understanding.
Everything you list are all physical objects. That you ascribe more value to one over another is a you thing, not something inherent to the object itself. For example, I have shirts I bought at Disney that I have never worn. They sit in a drawer taking up space but I do have the pins I bought and put up on display. I also have pins I don't display and collect dust while I have shirts I do wear.
I guess what I am getting at is why does the type of object matter unless you are saying there is a lack of other merch because Disney just makes pins. In that case, that would be incorrect as we all know that 92.67% of Disney park merch is spirit jerseys.
As for the last part, yes, they need more diversity of content within the merch categories as well as more categories. IE more Country Bear across pins, shirts, plush, statues, etc. plus merch types we don't see over and over again.