I gun hunt exclusively, and I have and will use a stand if one is available and the conditions are right to use it, and so does my brother who's also a gun only hunter. I probably do 90% of my hunting from the ground either walking or sitting against a tree, because I like the flexibility of being able to easily move if conditions change.

I don't know why your brother thinks that gun hunters do not use tree stands. The purpose of the stand remains the same regardless of the type of weapon used, which is to get the hunter up and out of the deer's line-of-sight. Stands are also useful for gun hunters to allow them to take advantage of the rifle's reach, because the higher vantage point allows the rifle hunter to see farther, have a less obstructed shot, and ensures that he's almost always shooting down toward the ground for safety.

Mike