I will refrain from pointing out your spelling error.
So, if it is only ignorance or not caring, I am wondering which category my 86 year old father would fall into. He left school during the war and so did not have the benefit of the education most of us have today. Although his grammar and spelling are less than perfect, this does not mean that he has nothing interesting to say. Similarly, I do some contract work for woman whose emails and texts are less than perfect; ignorant or lazy? No, in fact she is extremely intelligent and hard working, but educated in Russia, English being her second language.
Also, I don't understand why the Grammar Nazis are so keen to point out people's spelling or grammar transgressions publicly rather than privately. Could it be that not only do they want to correct people, but they want to be seen to correct people? If I read a post on this forum that has less than perfect spelling or grammar I can usually understand what the writer means. If not I could ask for clarification, but if I did feel the need to correct someone I would do it privately. Firstly because it is just good manners, but secondly because I am not particularly impressed by people who are more interested in form than content.