Now think about it this way. Many of you reading this might have an air conditioner at home, so you might know what this number on the display of the indoor unit means. It means degree Celsius, a unit of temperature. Even if you don't have an air conditioner, like me, you might have had the privilege of learning it in school or someplace else, that °C means degree Celsius. Now what if somebody never got a chance to know this? Neither was he privileged enough to have a closer look at an air conditioner at home or workplace, nor did he get a chance to study science. Would you make fun of him, for his ignorance? Or would you give him a word or two about his lack of knowledge and make him understand stuff? I am sure you would've taught him.
Now is the time, when people take pride in correcting other people's grammar when on the Internet. It is in vogue. Insulting somebody just because he or she speaks in broken English is cool. It immediately makes you look like a badass. It gives people an idea about your intellectual prowess. It clearly states that you had the privilege to attend a good English medium school and had the chance to read nice books.
Think about someone who didn't get to attend a good school because of his or her personal problems. They never got to read good novels. From all the schooling they got, they are probably trying their best to speak good English. Yes, I agree some didn't take the efforts, but there are those who actually never got a chance. Life is hard. Not everyone is born privileged. You, me have no idea what the fuck people have been through. So before judging and making fun of people in public for their language, just to get that two second of fame of yours destroying somebody, remember, you can actually correct him or her politely and earn yourself a friend who looks up to you. Isn't that better?
Speaking with proper grammar is good. Without it is fine too. Language was meant to be a way to convey thoughts and emotions. Let's keep it that way. If you are understanding what a person is saying, even with broken grammar, why not pay more attention to what he or she says and less on being an arsehole. I am sure you'll have more friends that way.
Thank you for reading.