Hello...
I quite often watch TBBT, I love their interest in comics as I also was a huge Marvel and Dc comic collector...Sheldon is amazingly intellectual but gets treated like a child by his friends...in this particular episode they were discussing the Raiders of the lost arc and how Indiana Jones doesn't change the outcome of the film...I haven't seen this film...
Sheldon behaves like a child so he gets treated like one. It's a classic comedy set up / constant source of jokes. Same as Joey in Friends / Niles in Frasier etc.