I'm sorry @Flaiban , but I agree with the reviewer. Fotos and Art should follow the composition rules of the masters. First you have way to much empty space and your subject line is not level.
Photo wise, your highlights are overexposed and your shadows are under exposed.It is also quite noisy. If you return the photo to its original exposure you can see how your highlights flooded the area around them. Also there are several overexposed sensor pixels that are vissible. Also there is a IP violation because the name of the modem is vissible.
So yes Adobe was correct in refusing this photo. If this is EXACTLY the way you wanted it to look, then I suggest you try to sell it on your own platform.
Adobe is not in the business of teaching us photography but they and this forum, can help us learn our mistakes. I hope my comments and observations can help you becoming a better stock photographer.