True, but there's also online dictionaries which is really a 2 second job to type in the word and see what it means if you're not sure about it. The problem, however, is that people automatically assume someone's writing must be terrible if English is their second language. I'll admit that my first language made me terrible at English grammar and structure, but that didn't stop me from telling my English friends to slam a ruler on my fingers verbally if I didn't type correctly. If I hadn't done that, I wouldn't be where I am now. I really love writing, so I needed to make sure my first language didn't get in the way of that.
In any case, though, there's just the outright bad ones who make us all look bad. But in the end it all comes down to priorities. I've come across plenty of writers who told me to take my advice and shove it where the sun don't shine because they felt they didn't need to improve. Unfortunately for them, that's the whole point. We improve because there's no limit, just like knowledge has no limit.