I had this question in the past. My husband (who is also my GC) said...No.

I was thinking it was some humongous problem. He explained that I will never see or care. The cabinets have a back panel, etc, etc,... I agreed reluctantly with that logic in our case.

However, I would definately want a back to the sink cabinet, even if no one else would ever look inside there! I would,..

If it's an outside wall, I'd consider it. However, it's really not necessary.

If it's an exterior wall, I'd say definitely use drywall! Yes, some GCs skip this step, with reasonable explanations, but it results in poorer air sealing outcomes. Drywall is so cheap; I wouldn't consider skipping this step to save time or money.

It also serves as a firebreak.

Thank you everyone for the perspective. The only place I'm considering omitting drywall is at a low knee wall (counter-height) between two interior areas. It's below a large opening between the kitchen and dining room. Functionally it's like an island back wall. All the exterior walls, and other interior walls will be drywalled.

The sink run of cabinets, below the opening to the next room, is where I'm considering omitting the drywall.

From the other side:

So did you skip the drywall. .and now?