The real difficulty with viewing gender as a social construct is that it means its existence is relative rather than absolute -- in other words, it's not objectively real. People often make the mistake of assuming that only the material world is objectively real; but, as the article points out, people believe that love is real, and love is an intangible.

Borders are not real in this sense. They are projections created by man for reasons they find useful, temporarily at least. When they cease to be useful, they will change or vanish altogether. But we cannot look at gender that way; gender roles, gender expression ... these things are, at least partially, relative; but gender is different.

You may say that "gender" is a construct in the sense that all words are constructs. The word "cat" is a construct. But the important distinction is whether that construct corresponds with an objective reality. That's what's critical for us. We must see ourselves as objectively transgender, not as a mere thought experiment, to be valid.