Your work isn't the best, but there's quite alot of things wrong with it.
Flow: The flow of the signature isn't very good, you got c4d's going one way and the other way creating an unsatisfying flow, unless the background was a contrast from left to right, in that situation it'll work, but in your signature it isn't.
Creativity : You lack creativity in this signature as it isn't much but c4ds with a render stuck on top, the plain background which makes it look unnecessary just shows how you can't think of a suitable background, I understand that the background is on the theme of "darkness" but the creativity is nowhere near the type of render that is supplied in this signature.
Lighting: You need improvement on lighting because the signature is very dark, the only source of lighting is the lighting from the render itself which isn't enough to to give light to most of the signature, you should add lighting in many ways, E.g Using white soft brushes, using lowered opacity brushes etc. The rest of the background is completely black, the render lighting is ONLY on the render which makes it stand out, the rest is black with some random c4d colours sticking out.