More accurately, I (and I suspect many others) seem to put too little weight on the value of identifying crucial considerations and of hacking away at the edges of open problems, rather than trying to come up with full solutions in one go.
Merely identifying crucial considerations without a full solution can seem off-putting; it requires admitting that one is confused, possibly in the face of others who claim to have a full solution and not be confused, and sneer at your apparent stupidity for remaining confused. (Theoretically, one might expect those boosting a particular position to deploy sneering at those who remain uncertain or confused as a bullying tactic leveraging social anxiety against non-believers, regardless of the correctness of the purported solution.)
Or sometimes everybody is openly confused and no solution has been proposed. In such cases, one can feel like anything less than a full solution is not publishable and should not be put forward.*** There could also be credit anxiety; if one puts forward a partial solution, then someone else might pick it up and complete the solution and get some of the credit. If one one has an advantage on solving the subproblems, then one probably has a compounded advantage on solving the whole thing, so there is the least risk of having to share or cede credit by only submitting full solutions (vide Gauss).
In particular, sometimes identifying a good thought experiment (or meta-analytical collection of thought experiments) can be the biggest step towards solutions, even if one does not initially have a solution to the thought experiment. (It feels like there might be an extremely deep and possibly even fundamental analogy to lemmas in mathematics here. I.e. choosing a solution to a thought experiment is equivalent to picking a model in which some corresponding lemma holds.)
(*** In similar situations, this might sometimes be a good thing. I've often been in a situation in which a math problem is posed to a group I'm in, and my instinct is to cautiously keep quiet until I'm confident I have a promising line on the problem. In such situations, others who are less reticent, however, often just say what they're thinking out loud from the get-go, obliging the rest of the group to abandon their own attempt in order to respond to the person who piped up. This usually ends up with some subset of the group dominating the group's attention with their attempt while everybody else just sort of sits there confused or miserable.)