The term “electromagnetic hypersensitivity” is a term to describe a number of effects. It's not that anyone denies that these effects don't happen. It's the fact that numerous scientific studies have failed to make an adequate association between the electromagnetic radiation and the effects themselves. So the causes of the symptoms are unclear, from a scientific point of view.
There are suggestions that they might arise from environmental factors unrelated to the EMFs. We don't know.
Yes, there should be more study. I think many of us have said that. More study is the answer, and there are ongoing studies.