As I have gotten older when I read something someone writes, if there is huge grammatical error I become fixated on the grammatical error and miss the actual message.
I used to be that way, especially after I had taken an editing course where we were tasked with going through some local newspaper articles and marking them up. Seriously had to stop reading those for a while as they are usually riddled with mistakes.
I can relate to this. It's hard to understand what message is being delivered when most of it makes little to no sense. I find myself wanting to reply with "huh? You want to try that again?".
I write for a living.
I write in English as a second language. I learned English from people who themselves were teaching English as a second language. When you are using a second language for your profession you are also prone to making mistakes.
However, I also have a strong dislike towards people who make grave mistakes and still call themselves writer.