So, do you mean to say if a person cannot speak/write perfect English, he/she should stop communicating with English speaking people? I think everyone has the freedom to communicate and everyone learns with time. What if you need to communicate with someone in a language you are not much aware of?
Well; you can very well communicate with English speaking people. But if you do, make sure you get the basics right. You need not write grammatically perfect English. But you sure need to be able to put together a couple of sentences that are at least comprehensible.