Much like navel piercings, a properly pierced industrial barbell is heavily dependent on anatomy. Forcing an industrial through ill-suited anatomy can result in physical damage to the surrounding area, warping of the ear, scarring, and even tissue loss in some extreme cases.
If the scapha, or flat, of the ear protrudes past the helical curl, or shell, then the barbell shaft will place too much pressure on the scapha and will cause physical damage to the ear. This damage can be in the form of a cut created by the barbell or the ends of the barbell migrating out of the ear.
Another reason we will refuse an industrial piercing is if the helical curl or forward helix is too shallow to allow a proper angle to be aligned and pierced. To put it plainly, we cannot pierce something that does not exist. Attempting to force a barbell where it cannot safely fit will lead to a painful warping of the ear.
There are certain cases when we can create a modified industrial, but they require extremely specific anatomy. As ever, your safety is our number one concern, and every time we say no, it's due to that fact. We sympathize with your frustration and your disappointment, and we are always happy to offer a different kind of piercing whenever we encounter this kind of situation.
In the first picture, we have an industrial barbell not originally pierced by us that was expressing issues due to a fairly shallow helical curl. Because of the pressure caused by the barbell, hypertrophic scarring began forming.
In the second is a fresh piercing by our head piercer. The forward helix and helical curl both have enough depth to allow the barbell to pass through easily, and the scapha is shallow enough that the barbell doesn't touch any part of it.