I think people just want stuff to harp on. They shouldn't all be expected to have the same articulation. They are not the same suit. And I wouldn't expect a Cap figure that has full combat boots to have the same ankle articulation that one with shoes and gators would have. No matter what order they are released in.
To expect a newer released iron man suit to have the same articulation or better as any older suit would be the same as expecting every human figure to have the same or better. Some figures have full 360 ankle flex and others don't. And each iron man suit is more unique then most most human figures (i.e. The mk3 is more different then the mk42...then...falcon is different from Fury or any other human.) so if any human figure has the articulation then they all should, by that logic.
The mk3dc can do more poses then falcon and cap and blade. Articulation is not the defining trait of hot toys, accuracy is. So, I don't see why it's an issue. There should be variety. I'd rather it have a little less ankle articulation but be more stable. Both my original mk3 versions have less stability due to wear on the ankle joints. And those where nearly half the weight.
It can't do every single pose with super articulation. But it can do every single pose a full 1/1 suit could. Shouldn't that be the standard?
wouldn't it be more stable with the feet being able to sit flush against a surface?
also, i think the complaints about it are warranted. it doesn't mean that it's a bad figure, it just means that it has a flaw. they've achieved better articulation with the other armors.. and considering this is the newer one, people expect improvements, not regression.
personally, i'd much rather have the ability to position the ankles flush THAN* not have it because there's a possibility that it might wear over time.
lastly.. let's remember that this is a $300+ figure. once you get up to those numbers, people are going to have expectations that are on par with the price tag. so, if they own a $20 6" figure that has much better ankle articulation, well, that's bound to annoy some people which is understandable. people don't want to look at it and say "eh, at least the articulation is a little better than caps".. that's just not how things are going to work, especially when there are plenty of other armors that achieve better articulation.
and to reiterate, i'm not saying it's a bad figure, just that it has a flaw.