Validation is actually very important, more and more people are accessing things through mobile devices and integrating websites. Most people are lazy to validate after its been done once but in the long run all those errors will pile up and eventually someone will need to clean it up.

Everyone complains about IE and its flaws and why it can't stick to standards. The same goes for us programmers, we need to stick to standards so things work right, if we don't we are p-issing someone off somewhere.