Although the steady drop in passengers on the AMS route is alarming and needs addressing asap, a 60%+ load factor is healthy for a business route and still profitable for KLM.
What does concern me is the fact that KLM have recently bought more E190s to replace the F70s, or in other words, a 98-seater aircraft to replace a 79-seater aircraft. Unless DTV can somehow grow the route, I think this is what will eventually kill it as at the moment, I doubt we can make the jump.