Some users don't like syntax highlighting for various reasons (e.g. external editor doesn't work etc.), see e.g. [1,2]. It would be nice to have an option (probably in global Jenkins configuration) which would switch on/off syntax highlighting.

[1] http://jenkins.361315.n4.nabble.com/HTML-syntax-highlighting-boooo-tp3701399p3701399.html
[2] http://jenkins.361315.n4.nabble.com/Text-area-to-enter-description-is-now-syntax-highlighted-tp3696066p3698932.html