That is typical of pretty much all BMW trunk lids and SUV tailgates. If you push your fingernail into it you will see that it is not metal and has absolutely zero to do with the paint itself. It is some sort of silicone sealer that BMW likes to use around the edges when the metal is bent. Maybe to keep water and dirt out or something. Even the inside of the trunk lid on my e36 325i has this material.

The dealer is going to laugh you out of the showroom if you bring it to their attention as there is nothing wrong with your car. IMO, it really isn't a big deal. My e53 also looks exactly like yours.

Also, I don't really think BMW paint is bad. The paint on my 14 year old 325i looks as good as new with only an occasional coat of wax and there is absolutely nothing wrong with the paint on my e53 other than some stone chips in front.

Lets be honest here, it is a far stretch to compare anything Ford or Chevy to BMW quality.