If you're referring to the Turing completeness, the algorithm and cards that were found require both players to be acting in concert to achieve the Turing machine; either player could stop at any time. I don't see the fact that players can choose to act strangely in a game to be a reflection of the game itself.
If you're talking about things like combining effects together that happen to cause an unbreakable infinite loop, then I'd argue that you're wrong; there's a rule that defines unbreakable infinite loops as a tie, so you know whether you won or lost (i.e. you did neither; it's not an xor, although it is a nand).
Your first statement is no longer true with the newest approach: it only requires a tournament-legal deck and the player piloting it to set up (and it could do so turn 1, though it's very unlikely to do so), and once set up it continues with only mandatory actions (neither player has any choices to make in the game, though either player could in principle concede).
But such things are not something which comes up in general play in practice: to set up such a machine you have to ignore several opportunities to just win the game. I've yet to even see an infinite loop which causes a tie.
> 104.4b If a game that’s not using the limited range of influence option (including a two-player game) somehow enters a “loop” of mandatory actions, repeating a sequence of events with no way to stop, the game is a draw. Loops that contain an optional action don’t result in a draw.
One (very contrived) example is the "three Oblivion Ring[0]" loop. Start with no non-land permanents on the battlefield, then cast an Oblivion Ring. There are no valid targets for the "ETB" (enters the battlefield) trigger, so nothing happens. Then cast a second Oblivion Ring; the only valid target is the first Oblivion Ring, so it's exiled until the second one leaves the battlefield. Finally, cast a third Oblivion Ring; the only valid target is the first Oblivion Ring, which is then exiled, causing the first one to come back. The only valid target for the first one is the third one, so that one is exiled and the second one comes back. The only valid target for the second one is the first one, so that one is exiled and the third comes back. This goes on infinitely, assuming no player has any cards that can respond to the ETB triggers by either countering it, removing the Oblivion Ring currently on the battlefield in some way, or putting another valid target for an Oblivion Ring on the battlefield. This isn't likely to ever happen in a game, but with the current rules, it's technically possible.
That rule is exactly where the the construction used becomes interesting: it's built in such a way so that if the turing machine halts, the player who set it up wins the game. If it doesn't, by the rule above, it's a draw. So it's fundamentally impossible to tell the result of an arbitrary setup (and in practice you could set it up such that it halts iff some unknown conjecture is true).
Regarding the oblivion ring loop, there's an example of it being used on MTGO, which doesn't end well (basically seems to crash the server and/or client): https://www.youtube.com/watch?v=AGXG5rNe_tI
> Regarding the oblivion ring loop, there's an example of it being used on MTGO, which doesn't end well (basically seems to crash the server and/or client): https://www.youtube.com/watch?v=AGXG5rNe_tI
Oh wow, I should have realized that somebody would try it out online just to see what happens! I'm not surprised it ends up with some sort of clash; given that it's Turing complete, the game engine obviously can't detect whether a current state will end up halting or not...
You can literally crash the game so you never know if you've won or lost.