The complaints are many and oft-repeated: “CSS has no grid system”, “the cascade is dumb”, “it’s broken”, etc. So why is CSS layout so hard? The obvious answer is that doing anything really well isn’t always easy. Most anyone can make a page in a modern WYSIWG editor (DW8/GoLiveCS2) in five minutes and have an accessible web page that nearly browser can read, and it can even look good–in that area we’ve come a long way–but it won’t necessarily look professional. There’s always a point in any field where your goals outmatch your abilities and I don’t see why CSS should be expected to be any different.
As for specifics, plain old CSS2 (1998!) can accomplish just about any layout you can dream up, but standing in your way more than anything else is the IE Factor. Even the upcoming version 7, which we’ll be supporting for a long time to come, will not support the table-* values for display that make multi-column layout easy as cake. Is it the CSS working group’s fault that a browser fails to implement standards for almost a decade? If existing standards aren’t supported, why should we believe alternatives would be/would’ve been? The sad part in the case of display is that IE also cannot change the display properties of table elements (the color chart is a table as it should be).
I’ve seen the point made that the cascade is great for text-styling, but terrible for layout. This person probably didn’t notice that the values of layout properties like display, position and float don’t actually cascade (aren’t inherited from the parent element). Oops.
Now, to give credit to the critics, there are a couple areas where I see CSS2 partucularly fails to deliver: 1) floated elements must precede elements that “wrap around” them in the markup. This is not usually a big issue since markup is easy to control, but at least one CSS3 draft addresses this. 2) the table-* display values mentioned before cannot duplicate table layouts that use rowspan/colspan. Again, the WG has put work into it, but don’t expect to see this anytime soon. Then again, non-IE browsers continuously forge ahead, supporting various bits of CSS3 like selectors, multiple backgrounds, rounded corners, opacity, speech, multi-columnal layout…