Does he not understand how to use a caulking gun? As long as the wall is painted with a good scrubbable paint and the joint between the counter and wall is caulked, it will be fine for a while. After all, caulk is what will go there between any granite backsplash and the counter, or any tile backsplash and the counter. The caulk is what works to keep the water from going behind the cabinet, not the granite or tile.

What hollysprings said.

I postponed a backsplash for "later" about 8 years ago when my kitchen was otherwise finished. Turns out I like the simplicity of the painted wall and don't intend to tile it. I am sorry I didn't do a 2" granite backsplash as a permanent thing but I would not do it if you are going to rip it out later.

The 2" backsplash could be expensive as a temporary solution. I didn't want a backsplash but had to have one because the gap between the granite and wall was too big for caulk. Try to make sure you get a tight fit. By the time I saw the gap on mine (it was covered with brown paper during construction) it was too late to fix it.

In a previous kitchen I didn't get around to the backsplash in eight years. There was no caulk and the cabinets were fine. I guess I don't throw buckets of water at my wall.