It's of course my own interpretation of what's important about music, but I've found that an arrangement sounds better if everyone's in tune and playing robotically than if everyone's out of tune and playing with a lot of passion. You kind of said it with "as long as a baseline level of intonation is in place"; if someone's playing way out of tune but with a lot of feel and passion... you get folk punk and "gifted kid" middle school folk ensembles.