Maybe it's an age thing? Ergo, the effect Star Wars has on us is dependant on age? We get blinkered as we get older; I know a fan, same age as me, who is part of what I tend to call ESB fans (ie, when it boils down to it, that's the only film they really like - although this fella actually thought ROTS was a good film - we all like the dark stuff I guess) who said he didn't enjoy TPM because he'd moved on to films by Tarantino by then. Personally, I think Tarantino is a talentless hack who rips off the films of others and thinks no-one will notice.
Seriously, though, Smith isn't the first to compare Star Wars to Shakespearean tragedy. I actually thought the tragedy of the romance in AOTC was very Shakespearean - go on, shoot me down in flames! And Jar Jar (I may as well go all out here) is a modern day Falstaff, no?