Proprietary isn't bad. Open isn't great. Proprietary vs. open is bad. Proprietary + open is great.
Proprietary implementations are a (sometimes) necessary interstitial step towards great open implementations. Save the "VS." narrative for Street Fighter II.
True, but Flash is a closed standard with a closed implementation. Adobe likes to claim it is open - but the fact remains that not only is it impossible to write an open implementation of their incomplete spec, but Adobe has actively sought to keep core components proprietary even in spec and prevent competing implementations.
That's the part that irks me about Adobe's role in this issue - they're playing themselves and Flash off as this open savior of the web when they've actively been evil in that regard. If you're closed, great, do your thing; if you're open, then actually open your spec - don't open part of it and then go after the other half with lawyers.
Apple is calling the kettle black with the proprietary argument. We can drill down to specific layers but the effects are the same to the developer coding on that layer.
Again, it isn't a case of one vs. another. I wish we didn't need to take a side and finally come to a conclusion that both are good in their own ways. Evolution is key.