What is it about the dishwasher that harms knives?  The only reasons I've found are:   You could get cut... I personally have a greater change of getting cut by trying to wash them by hand. The blades can damage the plastic-coated metal shelves... so I put them in the silverware-holder instead of on the rack (it's 100% plastic, no metal). The blade could get nicked by being knocked into other silverware... so put the blade by itself in a section of the silverware-holder in the DW.   
Expensive knives can survive a trip through the dishwasher, but like others have mentioned, they can bump into things, end up with coatings of detergents and such, suffer damage to wood, etc. Why would you do that to an investment?  Cheaper knives will just straight out rust/corrode, even if you remove them and dry them right after the cycle. Yeah, you can scrub it off, but you're also losing metal from the blade, possibly starting rust in areas you can't dry, and generally degrading the knives. 