It's understandable that a few of the original enthusiasts (those who went numerous times to see Star Wars back in summer 1977), don't accept that revelation. Perhaps the two revelations are weak in a sense (especially the Luke-Leia siblinghood), but what about Empire Strikes Back and its prestige in the film industry? That was arguably the best sequel made... Haha... there is no need to remind anyone that sequels are almost invariably inferior to their predecessors. While Star Wars in 1977 changed the public's perception of all film, ESB tends to alter the way we view sequels: there's a proven fact now that sequels have potential in contrast to the originals. That may be subjective... but it's a common enough opinion to the point that it blends into the objective! The story arc of Vader being Luke's father is forgivable in itself then, isn't it?