No it is not impossible. English is quite easy (in most cases)no matter what your native language is. It might take some people more time than others to learn it, but that doesn't make it difficult. Try learning Mandarin (category 5) in comparison and get back to me.
It isn't impossible, but it isn't as clean cut as you're making it out to be IMO. I expect it's easier if your first language is comprised of mostly Latin characters, however (much like your example) if a person is coming from a language based on Cyrillic characters (Russian, Chinese, Greek etc) it will likely be significantly more difficult to become fluent in a language such as English (at least to the point where you can communicate decently).
Not only this, but things such as idioms and sarcasm can make it harder for non-natives to fully understand what people fluent in the language may be saying.
everybody not 100% perfectly english speachers = lazy for your view.
I don't believe anyone is a perfect English speaker on this forum. Even natives such as myself still make a good amount of mistakes when typing or reading replies.
No one expects you to speak English perfectly, however people do expect you to speak it fluently enough to convey your point. If you do not speak English fluently then people that do may think that your post is spam or off topic as they do not properly understand what you're trying to say. This is not anyone's fault, simply a problem with trying to communicate with a language barrier.