The day you stop learning is the day to bid farewell to the world. Ok, don't take me literally on that, just take the point! So I'm all for gentle corrections. It really helps in the context of continuous learning. Sure, where English is a second language for someone then more tolerance should be given, but help with learning might be appreciated if it is provided appropriately.
Good spelling, grammar and punctuation all make comprehension easier. Less interpretation is then required, a good thing as different interpretations can lead to misunderstanding, or worse. English basics are all about effective communication, its not a case of being a grammar nazi or nit-picker.
If you had not already guessed I'm not an English major. English was by far my worst subject: it was boring to me at the time and as one English teacher pointed out I'm basically lazy to boot. He did it in class, and with some frustration although I don't remember what I might have done to cause that. I am still amused by it though. Science was fun and quite easy, I so I worked for good grades in those subjects.
Nonetheless, I am willing to read many of the longer posts that some make if the poster writes well, including getting English basics right. These days try to do likewise. Teenagers being lazy is one thing, adults not making an effort is different. I'm less inclined to assist a lazy or inconsiderate adult in anything.
One of the attractions of this forum is that mostly the posters and posts are polite, generally articulate and often funny. And there is a broad skill and knowledge base that is truly a treasure. But the disagreements are often hilarious and it's all I can do to not add to the mess. Usually, but not always. Something nagging me about casting stones, even if not the first one. Its been obvious for some time that its winter in the Northern Hemisphere: the cabin-fever outbreaks are a dead giveaway. Easy to click on another thread if it gets a bit much.