Emacs, as far as I remember, must load the
.Xresources file on startup and read the font rendering settings from there. But mine does this only if I run
xrdb merge first and then start emacs. I think I have something misconfigured here.
As my emacs starts as a systemd service I've just added
ExecStartPre=xrdb -merge ~/.Xresources in the emacs.service. It practically solves the issue. But I still want to know why it's not working as it shouldbe?
Also, my .Xdefaults is a symlink to .Xresources and I use KDE on openSUSE.