I have a question on guitars .

blues90 , I think there's 3 possible reasons one would go through a lot of guitars.  "The" reason could be one, or any combination of these three.

1) The person is new to guitars and/or guitar playing and is in "exploration" mode.  They're searching.  A lot of the time, they're even searching for what they're searching for.  lol.  They don't even know what they really like or want yet.   I think almost all guitar players have been here for at least a short time.

2) One knows what they want, but haven't found "the one" yet (or the ones).  That can go on again for a short time, or a very long time.

3) Novelty.  I know a  few  people who go through a lot of guitars...constantly.  The only thing these people have in common is that none of them are in bands, or play live or play for any sort of income.  So, they are not in situations where they need anything specific to "do the job" right, or fulfill a specific need.  They don't have the  novelty  of new venues or new crowds or new situations or etc.  So, the  novelty for them is the new guitar.  This is easily possible for them cuz any guitar that appeals to their eyes or ears or hands will do.  There's no specific task (technically speaking) that the guitar has to fulfill other than being new.  This one doesn't just apply to guitars, I've seen this with people regarding all kinds of material things.

The above reasons are not absolute either.  Again, people can buy new guitars for any combination of the above reasons.

This is just what I have observed over the past 25+ years.  There will be exceptions of course.  I can't think of any example right now but they will be there.  This is just what I have observed and YMMV.

This is a great question.  Something I've enjoyed talking with people about at my local guitar stores many times.

Garland ,  LOL.   Nobody buys something for no reason at all.  There's always a reason for someone doing something.  Everything happens for a reason. (Both philosophically and scientifically speaking)

As you stated in the second part of your post, the reason may be desire.  Fair enough, that fits all my categories actually and I agree.  Even if someone doesn't fully understand the whys and wherefores of that desire, the desire is still the reason for the guitar being purchased.  Desire is a very broad, all-encompassing term: I just broke it down into specifics  for  the desire for the sake of the OP question.

Reason has everything to do with it and it goes hand in hand with desire.  One does not negate the other.  Eg.  I buy a chocolate ice cream.  Why did I choose chocolate and not vanilla?  The  reason  I chose chocolate and not vanilla is because I don't like vanilla; I like and therefore  desire chocolate.  I would not buy vanilla because I have no desire for it therefore no reason to buy it unless the reason is that I'm buying it for someone else who does want and desires a vanilla.

It falls under the truth of cause and effect.  For every cause there is an effect and for every effect there is a cause.  Everything happens for a reason.  Scientifically speaking, even when it comes to the intangible things like desires, emotions, thoughts, etc. everything happens for a reason.

So, here we are, discussing the implied OP question by blues90 , as to the reason why some people go through more guitars in a year than he's had in his life. 

blues90 ,

In life people choose what they are happy doing.
Yes I buy a lot of guitars, they are not expensive guitars, it makes me happy trying different guitars, Yes I have had sellers remorse but you can't keep them all.
If I was wealthy there are loads of guitars I would like,
Now I have friends that go out drinking beer every night, they spend far more than I do on Guitars.
Loads of other people take recreational drugs, they spend far more than I do on guitars.
I have other friends who on mad on cars, they spend far more than I do on guitars.
I have other friends who are mad on motorcycles, they spend far more than I do on guitars.
I could go on and on, but I think you get the idea.
What I'm trying to say is you spend your money on things that make you happy and that you can afford.
Buying and playing guitars is far better for your health than a lot of other pursuits.
Or another option is not to spend any money on other than essentials, and die rich.