We give those who break their legs a crutch for a few weeks while they gain the naterual strength to hold themsleves up. We give beginners an electric tuner while they gain the ability to tune. We let them keep it for life because the electronic arbitrator is a useful tool when there are arguments. (A better tool would be someone who everyone agrees has perfect pitch)

When I first started with my Mandolin I didn't have a chance of tuning it correctly without, I tried and broke an E string a couple times. (I knew enough to start with the smallest string, which won't damage the insterment, the G string could do damage in theory at least) Two nights ago I did the tuning and only used the tuner to get the one string on key, and then the last fine tuning at the end (I don't know how many cents, but it wasn't many). I expect that someday I'll be able to tune without it.

If you need a crutch use one. Being perfectly in tune by the tuner is better then being in tune to your tonedeaf ear, and clashing to everyone else. You can build tone deafness into good hearing with practice. (assuming you have good enough ears to begin with)