I think Chrisbid has it spot on. I call it the Emperor's New Clothes effect. It is hugely effective in the industry i work in, Home Theater, where people seem to think that the more they pay for their cables, the better their stuff will sound. People often will fight to the death to defend the "sound quality" of the cables they paid the equivalent of a house payment for, when I can use simple blind tests on them to prove they wasted their money.
I definetly know what your talking about a lot of sequals really dont look all that better take ratchet and clank. While i agree some things looks kinda samey i thought the characters looks so much better but i guess im fighting a bettle i cant win. Since no one agrees with me ill just stop trying know.