Based on my own experience and years of spectating flamewars I figure somewhere between 40-80% of any programmer's aesthetic preference is familiarity. I use Liberation Mono (probably because it was the default on some ancient version of CentOS or something) and I doubt it'd be anyone's first choice, but every now and then I'll come across something with its own defaults and it just bugs me.

On topic, the most obvious difference between Intel One and Iosevka is the radically different aspect ratio.