Expert provides 180 Law; Level 60 provides 200 Law and 120 Poetics; Level 50 provides (on average) 153 Poetics (though it's actually weighted higher than that because of increased incentive to do the six dungeons that provide the most Poetics); Trials provides 60 Law; and Main Scenario provides 140 Poetics daily.
So each day, that's 440 Law and 413 Poetics. My original estimate of about 40 days up there is off—it's actually about 62 for Law and 66 for Poetics (I'm assuming I was factoring something else in originally that I've now forgotten--I came to the 40 days figure several days ago). Those roulettes tally up to a bit over an hour and a half of game time (30 minutes for Expert, about 20 minutes each for L60/L50/Main, and perhaps 15 minutes for Trial) if you have somewhat poor luck in groups. Round up to two hours.
So, you're looking at around 2 months to complete the weapon, which is actually fairly comparable to Novus, Nexus, and Zodiac if they were approached at a similar time investment. (It's about 53 days if you do the Alexander route of 640 runs of that at about 10 minutes per run, for the same 2 hours per day). If you invested about 2 hours per day in Animus, you would be looking at about one month (31 days--270 Mythlox runs at 10 minutes each for the Mythology and roughly 2 hours per book), though that assumes a lot of luck with the FATE timers.
So you're right, Animus isn't as bad (discounting FATE luck, anyway). But the other three are still rather comparable (which I think you would agree, since you said you waited to do them until after nerfs). That's ultimately the only point I'm trying to make: anyone who completed the Zodiac quests as they were current really shouldn't be intimidated by the Anima one, and anyone who didn't, shouldn't really be surprised that this one is the way it is. The Zodiac Weapon saga had more player engagement than a lot of the content we got in ARR from what I can tell (I'd be interested to know what portion of the playerbase had a completed Zeta in 2.55), so it's not surprising to me that they're generally following the same patterns in creating the version of the quest for Heavensward.
(Regarding the Animus stage, though, it's probably relevant that it wasn't a "complete" stage in and of itself. To get from i90 to i100 with the full stats, you had to do both Atma *and* Animus, so in some sense, it's not surprising that it takes about half as long as some of the other stages--it's only half of the full stage.)
And just a friendly reminder regarding the crafted items: nearly all of them (with the exception of the one that requires Pterodactyl Leather) are made from relatively cheap materials. Even if you can't gather the materials yourself, you can probably buy them and have the pieces made (by multiple crafters, as necessary) for a notable fraction of the cost of buying the final products directly on the MB.
Just as one example, let's look at the Titanium Alloy Mirror (chosen mostly just because ALC is one of my specialists and I could look at the recipe while on the MB), using prices from my server (which are not intended to be representative--I'm just giving an idea of how much you can save going by the materials instead of the final products).
The Mirror needs:
1 Titanium Alloy Square (ARM Specialist): 5 Sphalerite (1,000 for 5 NQ or 75,000 for 5 HQ), a Titanium Nugget (3,500 for NQ or 8000 for HQ) and a Dawnborne Aethersand (40,000 NQ, 65,000 HQ): 148,000 if you go the safe route and get all HQ mats.
1 Holy Water (10,000 HQ)
1 Hardsilver Sand (1,200 HQ)
1 Vitriol (3,000 for NQ--no HQ up as of writing)
So that's around 170,000 gil (rounding up from 162,000 since I didn't factor in cluster costs to keep it simpler) for the materials to craft a Titanium Alloy Mirror. The HQ Mirrors are selling for about 800k on my server. That's like 1/4 of the cost. Even if you buy the Alloy Square directly, they're going for about 200k HQ, which is still around 1/4 of the cost (you just save a little more having it made).
But 800k is a lot less intimidating than 3.2 million gil for that step, no?
I'm not saying you'll necessarily get buy at 1/4 of the cost for each item or on every server, of course. But crafters do charge a hefty premium on the MB for items that are in high demand, and you can get around a lot of that if you take the time to get materials and then find one to craft it for you. Most crafters are happy to do so in my experience (really! We haven't had hardly anything useful to craft the entire expansion, most crafters are probably just excited to feel valued again).