You are conflating two things: 1. the loss of most of our hair 2. the evolution of what hair we have left, and why we didn't go entirely bald etc. You seem to be saying that because a theory to explain 1 isn't about the sensory function of hair that this means that they're arguing against the sensory function importance for 2. That isn't the case at all. They're not competing against each other, but theories for 1 and 2 can run in parallel. So please stop thinking that they're in competition.