> why does presentation need to be separated from content?
You can't think of any instance when you would want to access the content irrespective of the presentation?
Imagine if, instead of HTML and CSS, web pages were delivered as pre-rendered PNGs. Make a list of all the different things that would break. That's why presentation should be separated from content.
I'm not really following you. "Make a list of all the different things that would break" - these things are things that are in use today by real people. No hypothetical people involved.
You can't think of any instance when you would want to access the content irrespective of the presentation?
Imagine if, instead of HTML and CSS, web pages were delivered as pre-rendered PNGs. Make a list of all the different things that would break. That's why presentation should be separated from content.