I’m not sure in what way my brain is broken to cause this to bother me so much, but I’ve often found myself staring at Xcode after a long time, fixating on the antialiased text being hard to read. I’m pretty sure a retina display would solve the problem, but that isn’t an option for my iMac or MacBook Air. Instead, what you can do is pick a font which has bitmap versions included for small sizes1 and type this into Terminal:
defaults write com.apple.dt.Xcode NSFontDefaultScreenFontSubstitutionEnabled -bool YES
defaults write com.apple.dt.Xcode AppleAntiAliasingThreshold 24
Restart Xcode and the slightly fuzzy antialiased text will be replaced with slightly pixelated non-antialiased text.