Of course I prefer it when riders look for a stage win or a GC win. However, with 21 days of racing and 3 jerseys a maximum of 24 out of the 200 individual riders can actually get a win. The others either ride for a second place or ride for somebody else.
A grand tour is a test of endurance and recuperation. That is why certain riders who are well equiped to win smaller stage races don't do well in a GT. After the many miles a GT is long, a top 10 position is regarded as a great feat by many teams and sponsors. For riders a top 10 finish seems to be just as important, as only apparent GC guys who have lost sight of a top 10 classification seem to be interested in stage wins.
We fans might not enjoy a rider protecting his GC when we deem it meaningless (let's say places 6 to 198), for a rider it may be one of the few chances they get. If you are not the fastest sprinter, not the best climber, not a puncheur et cetera but you do have great endurance and recuperate fast, you still have a chance of a top 10 GC and that is the best that rider can do. No point in not respecting a rider doing the best to his own ability.