I'm not a programmer, I'm an academic. Topics in my academic specialty routinely get posted on HN. When they do, I browse the comments section, look for users who exhibit many signs of lacking rigor and/or intellectual honesty, and add to my filter accordingly, on the grounds that their opinions on programming topics are probably not worth reading either.

I'm also a Chinese person. China matters is like an extra AOS for me and so I apply cosmetic filters for the same reasons