I don't play MTG nor MTGO so I have no clue about the implementation.
But Theory's example explains what I mean nicely. Too literal translations only lead to trouble, just look how much confusion ancient texts are still causing us today. Heck, for all we know "nailing someone to the cross" was an ancient metaphor for pulling a simple prank. Okay, it probably wasn't, but you know what I mean. Context is everything.
Online games have different context than their real world counterparts. Real world games are often played in a more relaxed social setting, barring tournaments, where time is not an issue and human interaction is the biggest fun factor. Online games are often played to test one's skills or to kill some limited time. I use the internet mainly as an "in-between" activity rather than a highlight activity so to speak.
So not only is it really awkward to try to translate real world mechanics to the internet, it's also awkward to assume that they're played in the same manner or with the same intent.
I've always been a big proponent of the point counter and even the much debated Point Counter Extension, because I realized that playing online is already a variant of the actual game. So while using the counter has been dubbed a variant, I believe that the term stretches even further to encompass all of online Dominion. In real life, you can monitor someone else to make sure that he's not using any tools. Online you simply can't do that, so why not make all public information known to everyone? You can't prevent people from using tools behind their screens anyway, so why not embrace this fact and provide these tools in the first place?
I don't think it takes anything away from the game to just list all public information. For one thing, it will likely lower the learning curve of new players and that shouldn't be a bad thing. Too often now I see new players committing suicide by buying the last Province in a close match. That can be helped if they can plainly see they would lose if they'd do that. And if they can check the deck contents of both players, they can learn from that too: "I bought too much Villages", "I bought too much Terminals", "I didn't buy enough Treasure", etc...