It doesn't matter how long Kneen has sat on his domain. The only reason the domain has value is because Kneen found it worth registering, and Harsh now wants it. If Kneen had registered www.:-mgpdgwcpdgw.con instead, he'd have been perfectly in his right to do so, and no one (presumably) would be interested in taking his domain. So why should someone else get a chance to take it away just coz he wants to? As long as there is no company called workbetter, the domain might as well be gibberish, and gibberish.com is not valuable to society.
That is like telling that most of a billionaire's billions are not really worthwhile to them and that they are uselessly "squatting" on them when instead they could be put to good use by someone else. One's possessions legally acquired are one's own to do what one wishes with it! Including sitting uselessly on them.