Topic: The primary reason, IMO, of the abandoned guitar!
First, confession time, my primary instrument and long term passion is playing classical 'piano' although I still enjoy the equally satisfying diversion, if you will, of playing my acoustic guitar. Problem: If the piano gets too much of my time over the guitar, the left hand 'chord' fingers tend to lose their callouses and then it can be a case of going back to the proverbial square 1, viz., getting those callouses back again!
IMO, the primary reason some guitars "repose" in the closet or in the bag/case, is the hassle of going through the left hand finger callous thing ... again! You know the drill: the guitar, for whatever reason(s), is put aside for some time and then when the spirit moves, out it comes and after a few tunes those classic string 'groove' appearances show in the fingers followed by the, shall we say, pre-blister stage, then the blister [and the finger tip pain to the max] itself makes its appearance and it can take weeks or months to get the fingers in shape again with regard to the callous stage and, bottom line, pain free playing!
Here's the thing -- especially for beginners -- and if I've heard this once, I've heard it a thousand times from those who begin the guitar but then abandon it, "I really wanted to stay with it .. truly so .. but my fingers [left hand] are killing me.. it's as if I placed them on a stove and burned myself.. it's 'that' painful!" Well, it 'can' feel like that but I think the greatest error is made when those first [and indeed painful] blisters appear generally on the index, middle and ring finger and new players figure they should just keep going even to the point of doubling or tripling their efforts during this stage but this can be fraught with problems! Space the time out and let your fingers 'gradually' get used to the string press process. The tendency to go overboard can do more harm than good! Let the fingers 'adjust' over time where daily practice remains entirely doable but not in 'hours' or 'marathon' playing versus 'sensible' finger adjustment 'sessions' as the fingers adjust gradually. You'll often see [new players] what looks like small circular but initially white colored 'raised' looking blisters and this is the PRE-callous stage where caution becomes the byword where the 'proof' is playing and very quickly noticing how your fingers begin 'talking' to you ... as in "Owwwwwwwwww!" -- don't go overboard at this stage -- over time those white looking 'pads' on the finger tips will grow darker and begin to harden and get tougher by the day but don't 'assault' them during the hardening process! Take your time! And when they do start to harden where playing becomes a pleasure versus an agony, keep up the guitar because if too much time goes by [measured in weeks in some cases versus months] of non playing, the body itself will tend to repair what 'it' sees as fingertip 'damage' [!] and, voila, you're back to square one all over again! Or, worse, the guitar is relegated to the closet or guitar bag! Stick with it but 'moderation' is the key! It's been my own experience over the years that the 'majority' play a musical instrument for personal pleasure versus dedicated commercial interests so, bottom line, hey, what's the great rush! Let the fingers 'adapt' to their new role, so to speak, and enjoy!
Doc Tony