Was the scene you mention any less corny and unbelievable than Vaders death scene in ROTJ?-- it suits the plot development as did Vader's sudden escape from the dark side,maybe the series should have ended with the Emperor tossing Luke down that galatic plug hole and left everybody on a downer but with a believeable ending.
And of course the events that change him into Vader are still to be discovered-see my later comment
Nothings changed in any of the Star Wars series except everybody who views them has got older and a strange notion that plot,dialogue,character development and believability(lol) are suddenly crucial in these movies.
Lucas has the burden of dragging these storylines to a conclusion everybody knows,he's beaten before he starts.
As a special effects and fun movie this is great entertainment.
Also Yoda rocked!
Who played him and where was his character development,you may well ask?
Damn you George Lucas,we've grown up and we want realism.....