Check this website www.SaveIE6.com - http://www.saveie6.com/ and feel the pain of developers facing issues in customizing website for IE6. IE6 still hold a market share of 14% (reference http://www.w3schools.com/browsers/browsers_stats.asp) so no one can develop website without IE6 compatibility. IE6 behave much differently then IE7, IE8, Firefox 3.0 or Firefox 3.5. It is realy hard to maintain the same look & feel in IE6 and other browser.
“There is a famous saying "No Pain No Gain". IE6 provide you lots of opportunity to feel the pain. IE6 is the Land Of Opportunity to spend lots & lots of your time for fix small & big things in your website. Really there is nothing better then hard work and there is nothing better then working for IE6. Save IE6, Save Pain and Save Gain...”