I see this argument all the time, and I don't buy it. Continuity only ties a writer's hands if he lets it.
I know - I see this comeback all the time on the Internet, but writers and other creators just continue doing what
they know they need to do to tell their stories nonetheless and that's one thing that's
not going to change. Continuity mavens will continue to be frustrated and dismayed that creators "don't get it" and the entertainment industry will roll ahead anyway.
The only real way to avoid this is, frankly, to deep-six the notion of these eternally-renewing, endless franchises and properties altogether. Tolkein, or J.K. Rowling and Warners can "get continuity right" - more or less - because they're telling stories with a beginning and a middle and an end. If you want to watch
Star Trek or
Doctor Who or
Spider-Man from your cradle to your grave, though, you'll just have to accept this kind of continual mutation, reset and revision.
Just don't refer to old baggage, and the old baggage doesn't matter any more! Pretty simple.
Generally I prefer this approach myself - "retiring continuity," it's called - but how exactly do you do that with stuff like Supes' marriage to Lois when that no longer serves its purpose? The creators should have their hands tied throughout time because of creative decisions made by other people that the folks involved now feel are dragging the property down? Uh-uh; no way. After a while no one will want to work on the property except for fanboys who will cater to the biases of the hard core who privilege continuity above everything else, the audience declines and the property dies.