Strength Tanks

[Freyyy]

Monk didn't seem to have changed much as compared to some of the others, but I could just be doing it wrong.

Yeah it didn't change much, NIN didn't change much either. MNK basically just gained means to overcome his weakness when being forced to lose GL3 because of mechanics (Tornado Kick, the ability to stack Chakra and form-shift when there is no target to have a better come-back afterwards). Other than that, he only got 2-3 more oGCDs to weave in his rotation (Forbidden Chakra, Elixir Field, and Shoulder Tackle which was not usable at melee range before). Basically, MNK is now the only job which has always something to do with his GCD even when there is no targets on the field for 10+ seconds.
NIN just got a mean to refresh Huton via a combo, 1 direct damage oGCD, 1 buffing oGCD, and 2 threat-management abilities. The rotation didn't really change, it has even been simplified in terms of Ninjutsu usage and Armor Crush just really takes the place of one Aeolian Edge here and there.
These two jobs didn't get very much more complex at level 60. They just got more tools to keep doing what they were already doing at 50 (and a unique utility for NINs).
However, SMN, DRG, BLM and BRD all got their rotations improved in terms of complexity at some degree. I can understand how players can be struggling when first hitting 60 on these jobs, but now that we're in 3.1 it shouldn't be very hard for them to look at some videos or guides to help them improve.

[Sapphidia]

However, SMN, DRG, BLM and BRD all got their rotations improved in terms of complexity at some degree. I can understand how players can be struggling when first hitting 60 on these jobs, but now that we're in 3.1 it shouldn't be very hard for them to look at some videos or guides to help them improve.

Whilst I definitely agree with you, there's something else to bear in mind here. Those 4 jobs did get added complexity, but they also got big changes in terms of the feel and fun-factor of the class. YMMV of course, but "added complexity" isnt the only thing at work here.

Every class generally has a focus to their rotation. They all have 5-6 regular buttons they press in either a fixed rotation or a priority system, but they all have something else to manage. Monk is about managing the 3 stacks of GL. Ninja is mostly about Huton uptime and regular Ninjutsu use. Dragoon was mostly about weaving lots of OGCD hits in between an otherwise rather fixed rotation, but now suddenly it also has the management of the BotD buff to contend with, which adds the additional frustration of "oh no my buff fell off due to a weird boss mechanic". This frustration is something Monks had to deal with pre-HW, but DRGs largely didn't.

BLMs got a massive change where instead of just watching their mana and reacting to procs, they now have a very very fixed rotation that harshly punishes them if they're even half a second late hitting that Blizzard 4. Bards didn't really get a complexity change but suddenly they're a caster and can't move as much during their rotations.

Any player forced to play one of those classes would easily adapt and learn the new rotation, but the fundamental feel of those classes has changed massively. The additional rotation skills add in layers of focus and frustration that are far beyond what players of those classes experienced in 2.55, whereas Monk/Ninja by and large got skills that REMOVE frustration by helping their buff upkeep.

I can certainly see (and know a lot of people like this) DRG, BRD and BLM players just leaving the classes in droves not because it's too hard but because it no longer feels like the class they loved playing back in 2.55. It may be that the community buzz about how fun tanks are (particularly all the fell cleave memes at the start of HW) has made these previously dps-centered players at least dabble in tanking.