It's because your argument is nonsense. I was using Reductio ad absurdum to show how bad your argument was, it was a complete non sequitur. Just because I don't share your unrealistically optimistic assesment of Sheahan is only proof I don't share that view and nothing else.
Learn proper argumentation. It helps you not look like a complete fool.
I'd say the only non-sequiter here is jumping to conclusions.
Sheahan is yes a third line center right now, but he's still very young, and has had lots of success already in his rookie year. To completely slot him at 3rd his entire career would require a crystal ball. Twins point was a good one, and not absurd. Guys like Zetterberg were never projected to be 1st liners when they were drafted. Neither was Sheahan. To say he doesn't have any potential to make 1st line at this point in his career is absurd.
That's not optimism that's just argumentationizing