Why people like to use feelin instead of feeling?

People write like that because they are slowly becoming illiterate idiots. People says 'cuz instead of because they are either too lazy to write "because" or they think that writing "cuz" is cool. Also, when someone puts a ' on feelin, it is because the apostrophe replaces the missing letter. Which is stupid, because you could just write the missing letter.

Well, they put a ' on the end of feelin because they are shortening the word. When you shorten a word, you should put an apostrophe at the end to signify that you are shortening it. Whenever people type, they try to type as fast as possible, and like to shorten words. 'Cuz is much shorter than because, so people use that. Also, many people have a tendency to spell incorrectly, they think it's "cool" (personally I don't see how that could be cool but people are unpredictable these days).

Maybe they are typing so that it's read the way they actually mean to say it outloud.