I think the attitude of web design changes with the uprise of HTML5 + CSS3. There are three things to consider and kinda important:

1) on different browsers, pages will look different. Some designers go that way to accept this and create designs that in fact look a bit different on every browser, instead to enforce a pixel-perfect design someone drew in photoshop

2) you don't know on which device the page is viewed and what resolution or aspect ratio it has. Is it a huge TFT display? A smartphone? A mobile phone? An iPod? A tablet? Is it vertical or horizontal? --- I learned a new term, "responsive" layout... as I understood it, it describes that a webpage re-arranges and scales it's layout itself depending on the device a user uses

3) your website is a win, if it is suited for touch devices. So, why developing a page for each device, if you can have it for all devices at the same time? I have the impression that this is possible today.

Because of these reasons I quit with learning how to make websites. Making my last portfolio was a pain in the ass and I "just" did a static website. For my next website I'll hire someone or buy a template and customize it or alike. I can not afford the time to become an expert on these technologies to compete in this hell, just for the sake of saying "I did my website alone!"...