"Guys" is an exclusive label.
For example, where I'm from (West Ireland), the term "Lads" is often used for everyone regardless of gender. One might hear a lady say she's "Going out with the lads" when describing a night out, with even a mostly female group of companions.
Basically, we should try to not use language which excludes others, but in some cases the person is actually using gender-neutral language from their culture and does not intend to exclude anyone.
I understand how ingrained the “guys” habit might be for
some of you. It was for me. After several months of
concerted, conscious effort, I still slip and say it on oc-
casion.
So even the author herself used the word with completely gender neutral intent, but then she insists that others can't. It's like she's looking for reasons to be offended.Either way, that's no excuse to stop thinking about things.