Maybe in these cases it's more a matter of ego (or hubris), and admitting to others the inability of their own hearing perception to do it accurately.
YouTube is full of folks who think this way or believe that their tuner is lying to them, and after 10 seconds of listening to a player with a flat E string or sharp C string, I cannot close the browser tab fast enough, as it's line nails on a chalboard to me when the instrument is +/- 15 cents out of tune, yet the person yammers on, way out of tune...
If I am in a group setting, either everyone tunes electronically to some standard, hopefully A-440, otherwise I will just leave.
Maybe it's harsh or intolerant, but often I find the arrogance of not wanting to be in tune, and/or the willful ignorance of WHY it is important on part of other folks in the group, usually manifests in other personality deficits later on, and then the whole experience just becomes sour for all involved, even if I say NOTHING and try to live through the auditory torture.
OTOH, maybe it's just me and I've become a miserable, rotten, sociopathic person in my mid-life age...LOL