Isn't it frustrating when you open the blindfold and you see that you DNF'd by 2 xcenters or +centers?
If you are new to 5BLD and have been doing it for a year or 2, DNF by few center pieces, or few outer pieces feel frustrating. One you do a lot of solves, you kind of become numb to DNFs, although its tough to become numb to official triple DNFs (it should be avoided at all costs).
For me, getting DNFs is important, as I get more analytical about my solve and can gauge the amount of risk I need to take next solve. 4BLD and MBLD is a bit easier events, as you can get momentum going and get good solves. 5BLD is quite different, there are always some unexpected DNFs that we have to go deep and make sure we do not do the mistake again.
Also 5BLD is the event, where the competition is more with ourselves, rather than a competitor,. In 3x3, we get 6.1 second solve and the guy next to us gets 6.2 seconds and we win that solve, but in 5BLD, competitors are not that equal in strengths and the main competition and motivation to do the solve, is to improve oneself, and not worrying about other attempts, as they have different skill levels.