That Schubert example shows the power of not the composer who creates, but the marketeers who sell. Commerce enters the arts!
Yes, after hearing edited editions for decades, I imagine an urtext based performance might raise some eyebrows and quizzical looks leading to a presumption of wrong notes being played. I believe that scholarly urtext editors sift all the known evidence to the best of their abilities. Probably in many cases they discover the unshakable, uncontrovertible and immutable truth. In other cases they might go with the preponderance of the manuscripts' evidence. And it would not surprise me if in some more ambiguous instances they make a judgment call as an editorial board. Goes to show once again that we don't live in a perfect world.
Bach urtext editions have been often criticized by piano teachers. Bach's directional markings were sparse to begin with, leaving most interpretive decisions to the capable pianist. Teachers believe that the old more heavily edited editions were more helpful to intermediate level students who generally need more specific performance directions. Goes to show that you can please some of them some of the time, but not all of them all the time as Abraham Lincoln used to say.
I agree on the simplified collections of pieces. In the end I believe they do more of a disservice to piano students. In my own case as a kid, I came up with my own (and very different) solution to avoid the frustrations of not being able to play "big pieces" for my own satisfaction. Where I have always had an excellent ear, I used to develop my own paraphrases of sections of piano concerti, for example. Some were so good that the unknowing listener could not tell the difference between my paraphrase and the real article. My teacher used to frown on that and call it doddling and a distraction from practicing, but I found it very pleasurable.
You make a good point on the personalizations made by composers to benefit certain artists. There is an obverse facet of this too, that is so-call "emmendations" made by the artists themselves. I was listening to a notable playing a Liadov prelude that I had recorded. The notes in the coda were different, and I knew it was not a conflict of editions, as it's always played the way I had played it. Clearly it was an emmendation--which sounded far more beautiful than the way Liadov had written it! In fact Liadov might have even preferred it. But playing it that way would be extremely hard to justify in my opinion given the fact that it's simply not authentic.
Many, many angles to "the wrong notes".