Because some people don't use that term to describe themselves either, even if that is what they biologically are. CIS is a pretty good term, because it's very technically correct. Sadly many have been on the receiving end of debates where it is used a a slur, and considers it hurtful.
It also has the weird problem that you mostly see it in a "do you identify as cis", which I at least don't... I am cis, but that's not question. This leads to some really weird situation where you have teams of larger middle age straight, and cis, men, but you have one or two that answer that they don't identify as such.
This is very much off topic, but I'd personally I'd prefer that we just stop labeling people. Just use their name, it's fine, you don't need to know or even understand the gender of the person who makes a repairable flatpack toaster. It's an cool project regardless of who made it.
>I have no problem with trans people, just leave the children alone
Nobody is trying to “erase” trans people. 99% of the backlash that we’ve seen is because these surgeries and treatments are being given to minors.
Also, minors would receive hormone blockers - which are reversible and safe. ...and also still prescribed for cases such as precocious puberty.
Absolutely not true.