Earlier quoted context omitted.
This is me exactly. I can't stand the UI in FF. It seems to change too much and it's ugly. There are probably plugins to help with that, but I haven't invested the time to look into it. It's also hard to kick the Chrome dev tools.
How is FF ugly? I don't find the UI very different from Chrome and Safari.
I know that all that maybe sounds rather petty and maybe there's something wrong with me and it's my biases for some reason, but it just all adds up to a fuzzy notion of childishness and less than "down to business" feel. I say that as someone that used to exclusively use FF and shunned Chrome for all the various reasons mentioned by others.