The original text of these cards even say "force opponent to draw", which kinda tells me that they knew it could be a "bad" thing for your opponent in some situations.
I'm dubious of this. It seems more likely that those were intended to be used on yourself and were just written more permissively, either by accident or "just in case". There are, after all, punishing effects. Very early mill cards seemed more like anti-scry or anti-tutor than anything. You may be right, of course; that was well before my time. It wouldn't improve my estimation of it... in fact, it being a
deliberate decision seems worse.
I don't see the rule of losing when you have 0 cards in your deck as any more "random" than the rule of losing when you have 0 life. They are just two different ways you can lose the game.
It is, because lowering someone's like to 0 is very much the aim. More life is good, less life is bad. Your deck is completely different; in every other situation, drawing cards is good. It's not even like a punishing effect (like Nekusar) because a) it's the normal rules of the game and b) it creates a cliffhanger scenario, where drawing cards is good until, suddenly, you lose. A cliffhanger scenario is
potentially interesting, but usually just makes for bad gameplay.
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.