It's also worth mentioning that from a flavour perspective, one could argue that the "lose when no cards in library" rule makes perfect sense.
From a flavour point of view, playing a game of Magic is supposed to represent two (or more) Planeswalking wizards having a magical battle. The library is supposed to represent the individuals mind, made up of the spells they know how to cast.
It does, until you actually think about it.
Sure, my deck represents the spells I know. I can't cast anything not in my deck. That makes sense. But then, what does it mean to have four copies of a spell in my deck rather than only one? Surely, knowing more spells is better... but putting more spells in my deck is not. Rather, the power of my deck is more like the average of the spells in it.
It also doesn't explain why you would lose. So I forgot all my spells... so what? How is this different to having only five land cards left in my deck? If my board state is still sufficient that I can win, why do I even need to cast spells?
Perhaps more importantly, what then does it mean to draw cards? I no longer "know" the cards in my hand... but I can't cast them unless they are in my hand? Drawing too many cards is the same as forgetting all my spells (except I have to draw them to cast them)? They've moved into some sort of short-term memory but my lower-level brain functions have shut down? Honestly, it makes very little sense, and that's fine because it's just a game with a bit of theming and a lot of abstraction, but in that case I don't think one should make silly game rules off the back of it.
*shrug* I may be the only person who sees it this way but, hey, you asked for unpopular opinions.
You definitely make some good points here.
From my point of view, I think there are a few things at play here.
I think a library representing a wizards mind is supposed to me more of a representation than a one to one comparison. It's more of a thematic way to explain what is going on "in universe" and doesn't need to answer every single eventuality with a concrete comparison. Playing four of a card doesn't mean "I can remember how to cast this spell exactly 4 times and once I've done that I will
forget how". It's more in line with "this is a spell I am comfortable with and can cast with relative ease". If we look at it like this, I feel that it makes more sense.
I also don't think a library is supposed to represent memory, but ability. It's not a case of "what can I remember to cast" but "what do I have the ability to cast". If my opponent has driven me insane (milled me), my ability to cast spells is gone. It's not that I don't have the memory, it's that I don't have the capacity.
I kind of see it like this:
I run 4 copies of
opt = I'm a wizard capable of quick thinking and decision making. I can assess my capabilities and limitations quickly to help me better find the right answer for my current situation.
I run 3 copies of
Genesis Ultimatum = This is a spell I have studied extensively as I believe it will help my beat my fellow wizards. But it is harder to cast. I have to exert a lot more resources to do it.
I run a copy of Lurrus = It's a spell I've read about, but it's not key to my plan. Might come in handy one day though.
Within the context of this flavour analysis, I see drawing cards as simply thinking. If my opposing wizard has just cast a spell that summons a dragon, I need to think of what I can do about it. I might already have the answer at the forefront of my mind (in my hand). I might think of a way to kill it (draw a removal spell), think of a way to summon my own creatures to fight it (draw my own dragon spell), or might not think of anything relevant by the time it has killed me (draw nothing that helps). Again, to me it's not a case of memory, but ability, and isn't a direct one to one comparison.
I also think losing the game with 0 cards in your library is absolutely the right choice from a gameplay perspective too. Milling yourself out entirely is incredibly easy if you are trying to, and a lot of cards, decks and archetypes look to make use of a stocked graveyard. The potential to mill yourself out and lose as a result does a lot of work for balancing these kinds of decks. If you could just dump your whole library in your graveyard and not be punished for it, you'd be at a significant advantage. I see it as a similar rule to the maximum hand size rule. The game needs inherent ways to
balance it, and if you want to flout those rules, you need to play specific cards to allow you to do so (for example Lab Man and
Reliquary Tower respectively).
Also, I hope it comes across in my replies, but I am by no means saying that my view point is the correct one and anyone else who holds a different view point is wrong. This is just how I see it, both from a flavour and gameplay perspective. It's all personal conjecture.