IMHO, everyone who weeps about other not being able to tune by ear should at least be able to tune professionally themselves: That is getting a reference tone (say an A) of any frequency on which the ensemble agrees; then having tuned the A-string tuning the other strings on his/her own.
(To all

However, I lack the understanding when people appear to tell others they should not play guitar/bass when they cannot tune it by ear - what's the point?
As long as the ensemble agrees on the same tuners (read: reference pitch), they all can use tuners, why not? Even if a tuner goes defect, take one of your colleagues.
A tuner to my understanding is as a valid tool as is an overdrive pedal or preamp is.
I may be wrong. In that case, feel free to correct me