If I have to write a he/she, I usually write it as "(s)he", but I usually avoid that too, because to me it seems like I assume a male, but maybe female, which defacto puts an implication on the term that women are not as good as, or equal to their male counterparts.

The whole thing is ridiculous.

The only argument I've ever heard from anyone about why they don't want to use "they" as a singular pronoun is that it feels wrong, or that it's a plural pronoun (which it is not, and never has been). Neither argument is valid IMO, and the entire practice shifts the discomfort of the chosen pronoun from listener to speaker or vice-versa, depending on the situation. If someone wants you to use the pronouns they/them, and you have any respect for them at all, you'll do it, and suffer that discomfort for their benefit.