True. The problem is the default browser settings. They are middling to bad, almost universally, and you cannot really expect visitors to fix their font settings before opening your webpage.

In a perfect world the defaults would look great, making sans-serif a viable choice and allowing the few users who really care (beyond 'it looks good') to do whatever they want.

> You can't do anything (other than using Stylish/Stylus, I suppose) if the dev hardcoded the font-family.

Well, i just disable "Allow pages to choose their own fonts, instead of your selections above" in browser font selection dialog.