In the realm of discourse, expressing a problem one is experiencing and denying the existance of that problem are not symmetrical. The former is (1) an expression of frustration, (2) a search for a solution, or (3) an attempt to gather other viewpoints. (There can be overlap.) By contrast, the latter serves only to attack the legitimacy of the experiences and opinions of others.
(In case 3, I would consider it appropriate to share personal experiences that differ from the expressed problem, but that's quite different from the inherent hostility of denying the existance of the problem in the first place.)
Then following your reasoning, please explain then how stating that there is a problem doesn't invalidate the opinion of the people who don't see that there is a problem?
Because the two claims aren't symmetric. The statement "x is a problem" is a limited claim relating to the speaker's experience--it's true so long as the speaker (or anyone else) finds x problematic. The contrasting claim "x isn't a problem" is a sweeping claim relating to the experience of everyone else--it's false if even a single person finds x problematic.
Of course, if only a single person finds x problematic, it's highly likely that x isn't worth fixing. And depending on the costs of solving x, it might not be worth fixing even if its widely considered problematic. There can also be plenty of debate regarding the best solution for x. Consider the following analogy:
Let's say you're having a problem with your neighbors being too loud. You go to a city council meeting to request that your community enact a noise ordinance. Person A stands up to oppose your request, stating that they don't think that a noise ordinance is the best way to address your problem because <reasons>. Person B stands up to oppose your request, stating they think the costs of imposing a noise ordinance are too high to justify fixing the problem. Person C stands up to oppose your request, stating that
their neighbors aren't too loud. Person D stands up to oppose your request, stating that loud neighbors aren't a problem.
By definition, you're the only one qualified to say whether your neighbors' volume is a problem--whether or not something is a problem is a judgment call that every individual has the right to make for themselves. Persons A and B have respected that autonomy, but have suggested (respectively) that another solution might be better, or that the problem isn't worth fixing. Person C hasn't respected that autonomy, suggesting that the problem shouldn't be fixed merely because they don't have a similar problem, effectively prioritizing their own experiences over yours. (Note however, that Person C's experience may be relevant to Person B's counterargument, insofar as it contributes (albeit anecdotally) to the cost/benefit analysis B is undertaking.) Person D isn't merely failing to respect your autonomy, they're going further and implying either that (1) they know better than you what you consider problematic or (2) you're lying about what you consider problematic; both implications are inherently hostile, and serve only to attack you.
If my explanation or my analogy helped clear things up, fantastic. If not, I suspect that we may disagree as to what it means for something to be "a problem". Within the scope of a given community, I consider the set of all "problems" to be a superset of the problems of all members of that community. I suspect that you may be using an alternative definition, whereby within the scope of a given community, the set of all "problems" consists only of those problems that the members share. Is my suspicion correct? (If so, I'm happy to explain why I consider my definition to be more useful.)
