Definition of straw man
1: a weak or imaginary opposition (such as an argument or adversary) set up only to be easily confuted
You set up a strawmen argument that Tannehill supporters expect/expected him to become a superstar in the future and then dismiss it. I've been on the forum since Tannehill was drafted and practically no supporter claims that he is a superstar in the making. In general, I would argue that his supporters assert that he is a good NFL QB, with some exceptional skills, who has already demonstrated that he can do his job well enough, when healthy, for the Dolphins to be playoff contenders. He has the work ethic and attitude to improve his weaker spots (and I'd argue track record of improvement for those weaker areas). As with practically all QBs, he can't carry a sub par team over the long haul.
I can believe that getting Tannehill back healthy this year gives us a shot at the playoffs without thinking he is a future superstar. I can even think that if he is healthy, that he should be our QB next year without thinking he is a future superstar. I can understand and discuss disagreements with either of those statements. When you say that the disagreement is, and has been, his future superstar potential...not playing that game. And, in case you're wondering, I can even believe the first two statements here and think that we need to be exploring other options (better than Osweiler) next year for competition or to fill in if he goes down again.