The hard part about using the browser's layout engine is that it is limiting to the designer.
Web design is all about limits. The designer has to understand, and ultimately play along, the constraints the media imposes on him - otherwise he's not a web designer, he's just a guy coming up with pretty mockups.
(...) Or they would have to know about floats, and how to use them.
Sincerely, if a web designer doesn't understand how floats work, what are they doing working with the web in the first place? Web designers != Photoshop pilots
Web design is all about limits. The designer has to understand, and ultimately play along, the constraints the media imposes on him - otherwise he's not a web designer, he's just a guy coming up with pretty mockups.
(...) Or they would have to know about floats, and how to use them.
Sincerely, if a web designer doesn't understand how floats work, what are they doing working with the web in the first place? Web designers != Photoshop pilots