I've been playing DF for a while (since the 2012 release, at any rate) and I've always been able to appease my dwarves enough that tantrum spirals were not a problem. They happened every now and again, but I couldn't consider them problematic.
For full disclosure, I'm still on .40.08 - I have yet to upgrade, so if this has been fixed in one of the later iterations, tell me to stuff a crundle in my chicken tallow roast-hole and upgrade, and I will do so happily. From what I've seen fixed since .40.08 dropped, though, it doesn't seem dwarf sensitivity has been addressed. The fort is 20+ years old.
I have a mostly-ecstatic dwarf population. They have awesome 3x3 bedrooms that are nice enough that they get good thoughts from having it. I have mist generators at the entrance to the dining hall and the entrance to the fort. I have artifact armor stands and statues put in high-traffic areas so they have good visibility to passing grumpy dwarves. There are a few of them with some raggedy clothing, but lately my clothiers have been spitting out masterwork t-shirts like nobody's business, and most everyone has at least two or three masterwork clothing items and collecting more and more as time goes by - there aren't a lot of Bad Thoughts being generated by clothing, in other words. Vermin is under tight control. There are roughly 2700 alcohol units, and 4000 prepared food units (provided my bookkeeper isn't a lying elf-lover). There are a lot of parties, but I rarely have idlers and it's mostly children attending the events (I have set the pop cap at 100, like my forts in the past, 30 of them are military, so that keeps everyone exceptionally busy). All my dwarves are the equivalent of the over-excited Forever Alone guy - either really ecstatic or very happy.
And yet, the death of a single military unit has caused four separate spirals in four separate incidents. The first ended with one mayor and six children left standing and the elf liaison having to step over dozens of corpses to warn the mayor about dendrophilia. The second ended with the captain of the guard and three kids who survived. The latest two I savescummed out of because, well, the spiral was no longer fun, just obnoxious.
In the past, keeping them happy was a way to circumvent the spiral, but that doesn't seem to work any more. Now it seems like their oversensitivity has become a problem - problem enough that I'm getting uninterested in continuing my forts. What's the point of making a fort, now, when I know that all my FUN is guaranteed to come in the form of a tantrum spiral?
Tangentially, shouldn't dwarves draw some sort of stolid inspiration from a fallen military dwarf? "Do not mourn Urist McBodybag! He gave his life so you could drink asparagus ale and spit out more masterwork silk bikinis!"
While I'm not at the point of stripping off my socks and punching a Stonecrafter in the head, it's getting pretty frustrating.
Is it a bug? Is it getting addressed? Is there any thing else I can do to keep them from-- like ninjas --flipping out and killing everything?