These filters ruin the retro pixel art look by making things blurry, making larger pixels, introducing a screen door, and more.
I think there's an argument that pixel art was designed for CRT displays and thus optimized for it. I think of it like Pointillism: the work is made of little dots, but the point is for you to see the entire work blend together. And for low resolution works like retro games, they often hold up well on CRT (especially real ones). However, I think modern games with the pixel art aesthetic look best crisp.
To each their own tastes, though.