Your expectation of where Shawn should be developmentally on his timeline seems unrealistic. The last 2 QBs he has played against have MORE experience. One made several starts last year and had way more PT than Shawn, all while making several horrible mistakes that cost his team games. He appears to be a better QB this year because of that experience. The other QB is older than Shawn and has been in college longer. Not to mention is loaded with talent around him, as are probably many of the other underclassman QBs you are probably referencing.
Nobody is saying let’s wait until Shawn is a 5th year senior, then he’ll be good. I think his ceiling is very high and I think he’ll be great well before then. But keep perspective, he is a true sophomore who just made his 4th start as the full time QB. Anyone that saw the one full game he played in last year could see some of the warning signs of his vulnerabilities (ball protection, decision making). We all got caught up drinking the koolaid this offseason thinking all that would be fixed in one offseason. Those things get fixed with coaching but more importantly they get fixed with repetition in live games. What I saw yesterday was a kid that sometimes tried to make plays that he probably made in HS and he is quickly figuring out the margin for error is much slimmer (his fumble comes to mind).
I always thought Shawn would experience growing pains in his first several games, maybe his whole first season. Especially with replacing 4 Olineman and really having no safety net possession receiver that our last 2 QBs had (Docston and Diarse). He has his work cut out for him, but he’s going to get better and I think we’ll see it as this year goes on.