Hmm. You make good points.
sweatdrop I mostly have Tuner banned for the same 'time frame' story reason -- I don't want to actually go through the entire card catalogue and figure out which cards were introduced when, so whether it mentions those elements is the easiest method. Trying to stick somewhere close to canon without being too restrictive.
I don't exactly know how Synchro, XYZ, or Pendulum stuff fit into the lore here, either. It's complicated enough without those elements. If I did add them at this point I'd have to figure entire subplots around them to justify their existence in my head, which isn't exactly a bad thing, just a lot more work. Not to mention I'd have to completely rework my NPC decks if they're to have a hope of being competitive...
I dunno. I sound like I'm griping but if you really think it would make things more appealing, or more importantly more enjoyable, I'm willing to put in the effort. ^^;