I don't mind when people use 'u' or I'z, or anything like that. But affect and effect are two different words entirely. People who say 'U' don't mistakenly write 'Me'. It's not a spelling error, it's a meaning error. You mean to say one word, you say another. In my english accent, 'effect' and 'affect' are pronounced completely differently. This may not be the same for you, which is why you make the mistake.

The same with 'of'. You picked another word that means something different and put it in there - you didn't just misspell it.

There is nothing wrong with bad spelling - I'm not very good at spelling either. But it's confusing if you substitute words with other words that mean something different, but in your accent sound the same.

The way I speak, those words don't sound the same, and your sentence becomes very confusing. It's only because I've seen this mistake a few times on the internets that I know what is meant.