My first interpretation of "underlings" tends to have it be a somewhat derogatory term towards someone who is of some sort of lower status, which I took to assume (having much experience with this happening while working corporate and on other online forums) that retail employees were somehow lesser/less worthy of being listened to since they were generally further removed from decisions that the rest of the company made (as in, multiple interactions where I would see a conversation like "When working in Apple retail…"/"Shut up, you don't know anything, you just work retail"). The commenter has clarified their position so in good faith I would be willing to believe them but hopefully that gives you a bit more insight into why the way that was phrased was evocative of this to me.