It's not the basic tenant of bitmap fonts from the 90's or earlier. CRT pixels (if you can call them that) would simply never line up perfectly (certainly not horizontally but also not vertically if I remember right). Screen fonts were specifically designed to look good after a bit of blurring, so to reproduce their originally intended display on modern screen it makes sense to artificially blur them a bit.
CRT pixels always line up perfectly because they are drawn with the electron gun, not etched into the screen like EL, plasma, or LCDs. OTOH, they are never square. They are always rounded at the ends and usually overlap due to focus and timing.
