This is all over the place, from praise, to dislike, to let's compare him to the rest of the Buffalo pipeline, even to non-prospects (Mittelstadt).
Your assessment is his development is one thing (I disagree with portions); your assessment of his value is way off. I'd trade any of our 2nds this year for another team's Isak Rosen.
It's not all over the place -- the point of listing his strengths AND weaknesses (praise & dislike as you call it) is to show that I can be objective and see the positive areas in his game in addition to the areas I find concerning.
As far as Mittelstadt: the point here is that Mitts is still young enough to be part of the Sabres core as they go forward. He may not end up being that 1st or 2nd line C that he was hoped to be given his draft position and WJC performance, but even if he tops out as a 3rd line C or a 2nd/3rd line winger, I have seen growth in the areas of his game I wanted to see that make him both more effective and more versatile. That means while he is far from "untouchable", he can be a legit piece of the core going forward.
Conversely, I don't see Rosen as a core player for BUF, and perhaps any team in the NHL. He certainly is behind all of Quinn, JJP, Savoie, Ostlund, Kulich, Krebs, and yes Mittelstadt as well. Just in the same way I don't see Olofsson part of the long term core either. That is why I would trade Rosen before ANY of those other guys.
As far as the draft picks: yes, I would rather have the PHI 2nd rounder than Rosen. I think there could be a legit #1 starting goalie on the board where that pick is, and also the kinds of high quality complementary 3rd line types or #4 Dmen that this team needs to add to their pipeline.
It should go without saying that I can respect reasonable minds to disagree with that assessment, but it is unreasonable for you or anyone to say that I'm unequivocally incorrect or that it's a "breathtakingly stupid take".