"Thinking: The talking of the soul with itself." [1]
English is compulsary for a reason, not simply to improve how you communicate, but because the language in itself allows you to have a higher order of thinking.
I know I am going to be attacked for this, especially on a 4U Maths thread (English ppl help me here), but the fact is that English is more pertinent to the most important and fundamental issues of our existence. Do you think in binary? No, of course not. Maths, science, engineering, etc - "these are noble professions necessary to sustain life"[2], but English, English is making meaning out of that life.
English (or rather language, but we live in an English speaking country so I will say English) is the method in which we are able to define the human experience - it is the most important subect of all because it relates to the nature of humankind.
In maths, all the answers are waiting for you within the page - its all there to be worked out. It is the left-brain orientated (and there is absolutely nothing wrong with that at all) people in general who seem to have more difficulty with English because it requires us to draw upon our imagination and reasoning skills that questions the purpose of the universe.
English provides the advancement of the understanding of self through the abilities of self-reflection and self-examination, and by doing so, directs the individual in determining their identity, and therefore taking one step closer to enlightenment and an authentic sense of being. In comparison, mathematics allows the logical resolution to numerical and geometrical physical problems, as well as theoretical mathematical aspects of the world which has no real significance to the extraction of a greater understanding of existence.
[1] Plato
[2] Dead Poets Society