Coming from the comments in this question https://askubuntu.com/questions/16178/why-is-it-bad-to-log-in-as-root:

The sudo mechanics is in use so non-administrative tools "cannot harm your system." I agree that it would be pretty bad if some github project I cloned was able to inject malicious code into /bin. However, what is the reasoning like on a desktop PC? The same github code can, once executed, without sudo rights, wipe out my entire home folder, put a keylogger in my autostart session or do whatever it pleases in ~.

Unless you have backups, the home folder is usually unique and contains precious, if not sensitive data. Root directories however build up the system and can often be recovered by simply reinstalling the system. There are configurations saved in /var and so on, but they tend to have less significance to the user than the holiday pictures from 2011. The root permissions system makes sense, but on desktop systems, it feels like it protects the wrong data.

Is there no way to prevent malicious code happening in $HOME? And why does nobody care about it?