It's impossible to have a fair election without offering a blanco or NOTA-option. You must have a way to express disapproval of all candidates or even the system. So yes, people should vote NOTA if they think CR is an awful system. That's the entire point of it.
Besides that, purely practical, it increases the total number of votes so that there's a higher change of a 2nd round, so that someone isn't elected just because a large number of people don't really know what to vote. It also shows the difference between people not bothering to vote because they're lazy and people who honestly don't feel like any of the candidates are good.
As of now, we have a turn-out of 64% (118 votes). 11 of those votes (9% of all votes or 6% of all voters) have chosen the NOTA-option.