I guess you don't understand how stereotypes work. Sad. Expected, but sad.
The imagery of a GED neckbeard that you chose to paint is one that overhelmingly goes along with a low-income white man with a blue collar manual labor job. The main implication is that these are people with little worth in your estimation. Who they are and how they got where they are is unimportant to you. These are trash people in your pompous eyes with insignificant lives. You know it because you painted it. Don't back down now.
Are all "GED neckbeards" in this mold? No. There are plenty of GED holders without neckbeards and vice versa. There are plenty who are not white. But the racial sterotype of a white trash bumpkin is where you were going and it is intrinsically a white person in the stereotype. The insult doesn't work without it being such.