The prominence in grammar

Liz and John Soars give the following reasons to teachers to explain the prominence of grammar in their materials:
It is the mechanism that generates the infinite number of sentences that we produce and receive.
It is a tangible system, and can provide one element of a systematic approach to teaching a language.
It develops cognitive awareness of the Language. Language is ruled-based, and consciouss or sub-consciouss knowledge of the rules is the key to "generalizability" and creativity.
It conforms students´expectations of language learning.
It will be of assistance to teachers in the planning of their lessons.

I agree with the reasons mentioned above but for the first one, because I do not think that grammar alone can form sentences. In my view, grammar is the backbone of the language but it cannot work without its parts. We need all the systems in order to develop the language. However, I do agree with the other reasons mentioned, because grammar is something in which students rely on. It makes them feel safer when using the language, they like to know the rule and they generally feel that they do not learn anything if they are not taught some grammar.