In my opinion this misses the very simple observation that language easily allows us to communicate complex ideas with high fidelity and this type of common-sense view of language has been and remains important to understand the world -- both if you are a 6 year old or a scientist.
Constructionists accept the ordinary use of language and respect its usefulness. What we object to is the idea that this usefulness equates to identity with reality. This distinction is what we are getting at. It is important because if you view descriptions of the world as useful/useless rather than true/untrue then it enables you to adapt to new circumstances, reject intolerance, and avoid dogmatism. Please see page 231 of this book available on Amazon's look inside.
Your further comments misunderstand my view of ordinary language. I accept it, use it, and find it helpful. Constructionism in no way demands that we give up using words in their everyday sense. What it means instead is a recognition that the everyday sense of words can be overturned at any time.
It's an approach to language a bit like wishing for a sterile operating theatre. We would want the theatre to be completely sterile for our operation. In the real world a 100% sterile theatre cannot be achieved. That doesn't mean we give up and say what's the point of attempting a sterile environment if it's not 100% possible.
With language, the aim to understand and to be understood is a worthwhile goal. That we realise this will never be acheived 100% and that all utterances are subject to revision is no reason to give up communicating.