Is it correct to use single quotes for HTML attributes?

Question

Recently I\'ve been seeing a lot of this:

Answer 1

What's against single quotes?

You can have single/double quotes all over your html code without any problem, as long as you keep the same quoting style inside a current tags ( many browser won't complain even about this, and validation just want that if you start with a quote, end with the same, inside the same propriety )

Free support to random quoting styles!!! (yay ;D )