Since long time ago I have been thinking in two problems that I have not been able to solve. It seems that one of them was recently solved. I have been thinking a lot about the motivation and its consequences. Mostly because people used to motivate one of them with some very interesting implications. My conclusion however, is that there is a mistake in the motivation of the problem, and that, while being a really interesting result, it does not make any sense in the setting in which is formulated. As my opinion is not relevant compared to one of the experts in the area, I do not say anything. 
My question is if you can provide me some examples of conjectures that were believed to be interesting in the mathematical community because of a specific reason, but that once having the proof, people realized that the reason to motivate the problem  was not truly related to its solution. Or in other words, the solution of the problem gives no clues about the original motivation. 
I do not think that is relevant to specify the area in mathematics of the examples, because I guess it could fit in a wide range of areas. 
Ofcourse, some examples can be easily given from History of Mathematics, like the Goldbach Conjecture motivation, where the motivation is only a special case of the problem itself. But I am looking for more modern examples, preferentially with proofs given very recently.
Thanks in advance!
Best
Gonz
My interest in this is that I would like to give a talk in one of the seminars of the math department of my university. I want to convince all of them to think more often about the meaning of a problem instead of its proof.
I would like to use some examples before giving my opinion. I guess this post is long enough, I will continue if any of you is interested.
Best Regards,
Emiliano
I'd be happy to help you