there's a difference between proper and valid. a man waering a sunday dress in the middle of a snowstorm could be considerd valid - he's wearing the dress the way it was designed to be worn - but there's no way that's considered proper usage.

it varies from designer to designer, but personally, if your design can't easily fit into a tableless structure, your design architecture is flawed and needs to be rethought.

you can be a great graphic design and still suck at web layout - it's not the quality of the concept/graphics that's the issue, but how it's organized on the screen. this is often seen in print desgners. laying out booklets in indesign isn't anything like structuring a web site's base html, so i forgive them, but that's my opinion on people who primarily deal with web.