Let me be clear about one thing:
I do like the idea of PS2 classics coming to PS4, even if they have to be in digital form. Getting Trophies, along with full support for features like Remote Play, Share Play, Activity Feeds, etc., is definitely a good thing as far as many gamers are concerned.
And let's face it, not everyone on the planet already owns all the games Sony will ultimately bring to their new machine. Sure, the first 8 are pretty common, I'm sure, but I'm willing to be there will be plenty of PS2 titles that you either don't still own or never played, and will be available on PS4 with all the bells and whistles.
There's nothing wrong with that. However, that ain't "backward compatibility," at least as far as I – and many others – are concerned. To me, backwards compatibility means a machine can play physical copies of old games we've already got. That's pretty much the point of this feature, isn't it? So we can play games we have in our library without buying them again or hooking up old consoles? It kind of defeats the entire purpose if we're only talking digital emulation. But the bad news doesn't end there, as we see clarified in this article : It doesn't even matter if you purchased a PS2 classic to play on your PS3; even that won't work on your PS4, so theoretically, you'd have to buy the game a second time. …a hard pill to swallow if that disc is sitting in your collection, which would actually mean you bought the same game three times.
Perhaps Sony never used the term "backward compatible" when announcing this feature for PS4. Maybe only gamers and journalists have. If that's the case, we're the ones at fault. Either way, though, this is not backwards compatibility. Just wanted to make that abundantly clear.