Yes. But then I'm not saying they shouldn't be implemented consistently and predictably, so I'm not sure what the point you're making is. Also, I wasn't talking about "right now", I was talking about a future in which the file system is abstracted away from users. Which is obviously not right now.
I'm guess I'm trying respond with my points as they applies to multiple people here. Sorry if that wasn't more clear. I'd agree with everything you just said but the implementation needs to be solid and consistent whenever that day comes.
I didn't say they were. The tools (i.e. varied methods tags are supported) need to be consistent and predictable especially between apps of a particular object type. You wouldn't want tagging implemented differently between photo apps would you?