Here's the thing; I am technically from a "marginalised" group and yet I still often use what you'd call marginalising pronouns. I use them not to marginalise anyone, but because they're commonly used and there's no reason to not use them.
When I say "he", it's probably because I am a male so I default to "he", but that DOES NOT mean that I mean to "marginalise" women, in fact be free to substitute "she" in if you feel like it, it is sort of implied if you're a female and I am technically talking about all genders.
In reality, it's just faster to not watch every word your write for "inclusiveness" or "marginalisation", because I assume you're able to infer the inclusiveness from context.
If you're searching for offence, you WILL BE offended, even if no offence was meant by the original poster and by doing this you're actually marginalising the real problems marginalised groups face.
People aren't saying that you are trying to marginalise women and transgendered people. And if they are saying that you can safely call them idiots and ignore them.
What they are saying is that switching from "he" to "they" is simple and easy, and will make life better for many people. It's correct English, and has been in use since the 16th century, albeit with some push from prescriptivists.
You're right that in the face of things like rape statistics (women are far more likely to be raped by men) or domestic violence (women are far more likely to be killed by male partners) worrying about "he" vs "they" is a small thing.
> What they are saying is that switching from "he" to "they" is simple and easy
I get that and if I remember to use it, I will, but when I instinctively do not use it, because well, "he" still comes more naturally to me than "they", it should not be assumed that I am sexist, bigoted etc. because I made a particular choice of words that can be reasonably interpreted as not meant to explicitly exclude people, unless they're looking for it.
> will make life better for many people
It's true that it may make them feel better, if they're looking at every use of a gendered pronoun from a "it's sexist" perspective, but I'd argue that's unproductive and not really making their life any better in a meaningful way
> It's correct English
That's good, but that doesn't mean that it's "intuitive" English for everyone and they shouldn't feel bad for it.
- rape has largely been defined so that it is physically close to impossible for a woman to rape a man.
- The official numbers for IPV are very close and there is a strong reason to believe that female on male IPV is dramatically underreported (female on female IPV apparently has levels similar to male on female). The only statistic I could find for murder was murder-suicide.
If you're searching for offence, you WILL BE offended, even if no offence was meant by the original poster and by doing this you're actually marginalising the real problems marginalised groups face.