"Playing the game safe is relatively easy."
The way the quote says 'relatively', it means towards the game. The game has a hard learning cliff, but then you reach the top, it's easy to make a safe fort.
I suppose. I guess I was pushing for a more survivalist sense of the game as soon as I realized what was going on. Harsh lands, no traps, no danger rooms, I moved towards that after about 3 forts of feeling invincible. Even though 5 or so dwarves might die during a siege and we can't get to a reasonable source of wood until we breach the caverns, I don't define that as an "unhappy" fort. I think the OP's vision might be better suited as, "Forts which are established on perfect-ish embark locations, utilizing every single defense mechanic, with care taken towards perfecting every controllable aspect of the game, are all alike; every fort which without all of these factors is unhappy in its own way." Even then, there's design (which may or may not affect dwarves, but certainly affects the player's experience), ambush-then-tantrums, amount and types of of resources (particularly in the new version, which I have not yet moved into), landscape elements, and player patience and knowledge. Also, doing things perfectly right can actually be quite a bit of work! And, it's also true that if you take one, just one, aspect out of the equation (no military, or no traps, etc.), the situation gets a lot more complicated.
I guess I just don't like the idea that a "happy" fortress must seem like an identical experience to all other happy fortresses which have proceeded it. If we're talking specifically about number of dwarven deaths, number of tantrums, amount of starvation and dehydration, and relative unpreparedness for attacks, then yeah, "happy" forts are somewhat all the same. But there are so many more interesting variables that the statement "happy forts are all alike" is hard to justify. That's the game to me... you don't have to necessarily spend 3 hours genning worlds until you get the perfect spot, you pick a spot and deal with what you don't have. Or you do spend that much time, because you're totally into having the perfect fort. Neither is better than the other, they're just different ways to play the same game.
I think the topic begs, "What is an unhappy fort?" Does that mean dwarves are ready to tantrum, are tantruming, or are killing each other? Is a happy fort one where all the dwarves are ecstatic, or one where every resource is available in abundance? Unhappiness is a product of things I'm trying to fix; happiness is a result of things I've done. Both are part of the experience, and both lead to their own difficulties... a terminally unhappy fort destroys itself, and a terminally happy fort may be abandoned by the player.