But it's shared by whose standard ? It's pure conjecture, we see others basically as mere different versions of ourselves, and it works for the most part, but what if it doesn't and you're actually wrong ? Suddenly you get into the reality, people are having lots of problems communicating precisely because their life experiences are divergent enough to make it difficult to comprehend, let alone getting a chance to build on it with another individual. Fortunately no one is that different, we have a lot in common thanks to our cultures, but what if we were living in caves, would it be so easy ? Thinking of allegory of the cave, if you were the one to leave, assuming they don't kill you when you come back, do you think they would understand what makes you happy ?

Therefore, we can guess, and it's fine, it's doing the job, but that's where it stops, we make lots of guesses based on our own experience, objectively we are reflecting our own self, I can never get into your head to actually get a sensible feeling of what you really think, I would just mimic it and pray for the best, it's not exactly the same thing.

My knowledge about others in general is not that impressive, but Sartre, Heidegger, or even Locke have lots of deep thought around this idea that we can't do more than reflecting ourselves into the other, it's our only way to communicate, mimicking each others.

As to know if a good philosophy is something that convey into the masses, well I don't have the capacity to judge it, but it sounds foolish to me, philosophy is not a competition, it's about substance, not acceptance, the quality of your ideas are not measurable by the amount of people who read you, otherwise, people like...I can't come with an American name, so let's throw a A.Soral –a french one notoriously known for being dog shit– who sells lots of book would be a better philosopher than say Schopenhauer who couldn't sell any of his work during his lifetime, it'd be foolish nonetheless. Although, I might've misunderstood your sentence, so I'll also build a bit around both ideas; To me, I've said this in another comment here, philosophy is mostly accurate because of mimetism, someone really smart (start with Aristotle) begin to think about the world, and gather people with the same purpose around him, and then suddenly, he (Platon) starts to write and describe his own view of the world, the next person smart enough to get into the work build his own ideas using the previous work as a fundamental, to better contradict it, and then it goes on ad vitam eternam, so concomitantly, most ideas are build bricks by bricks to suit our reality, philosophy is not something such as "this one is bad, but this author is fantastic", every piece of work is interconnected, there's no philosophy unworthy or absolutely false (as long as you deem it worth reading), any and every ideas will be used to enhance further our comprehension of our surrounding, hence when we use "philosophy", we don't think of an individual theory, we use them all, whereas if we dig into it further down, every individual has its own philosophy into a gigantic dialogism that we confront with each others every day of our lives to prevent ourselves from alienation.

In writing on my phone, it's hard not to lose focus writing posts like this, so excuse me of my possibly inaccurate topic.