I thought to pop in and offer a couple of thoughts.
Tuning one's instrument is the responsibility of a musician to do. Having the musical skills to hear if one's instrument is in tune or not is something so basic, that anybody who cannot do it needs to learn how, just for the musical principle of having this skill, not for gigs, not for studios, but for the desire to simply become better musicians with a steadily developing ear.
I've always said that many players aren't really interested in music, and a lot of guys on Talkbass show this point quite often. They are only interested in music entertainment! It isn't that not having the ability to hear if one's bass is in tune is the problem; it is that some players are OK with semi tone deafness and just aren't interested in finding out how to perform the same task that many 5 year old players can do with great ease. Too many people in music accept, justify and defend low quality in musical ability, from the academic to the art of it! I won't! And I suggest that some of you stop this as well! You are lowering the quality of musicianship in this country more and more by championing low standards, finding reasons and excuses for it. Tuning an instrument by ear is something so simple, so basic in musical requirements, that if one cannot even make the attempt to learn this skill, then they should never have expectations of much to happen in their musical lives.!
Get on board the train to higher musical levels, and quit justifying low quality musicianship as if it was a virtue!
Thanks for reading!