There's a constant dynamic going on between the expert mini fanciers (of which CSO artists are a fair representation), who love the flexibility of multi-part minis and are happy to work with them, and the average hobbyists who like a few options but don't have the same level of emotional investment in architecting each mini. As the former group are often closer to the artists and/or sculptors involved in 'Mech design, it feels like particularly desired minis (like the new Black Knight) seem weighted more in their direction.
The original Project Phoenix 'Mechs, for example, included some of the worst examples of "expert-grade only" minis - the reseen Marauder 9L, Warhammer and Thunderbolt being particularly egrarious offences in this regard. (Seriously. Why bother making the PP Thud so multi-part, when the legs can only go in one stance without major rework, and the left arm looks like it had a stroke. Seriously!)
There is a middle ground - consider the PP Archer. Yes, the missile doors are a pain, but it's a good dynamic striding pose, with separate torso & arms allowing for individual variations. And there are many single-piece minis - Quickdraw comes to mind, along with the powered-down Dragon ;)
At the end of the day I think IWM do a reasonable job catering to the different levels of skill & interest out there in the fanbase. It's just painful for any of us when a mini we'd really like ends up catering for the camp at the other end of the skill spectrum.
And it's worth pointing out IWM have revisited some of the worst offenders, and produced more reliable variants. The Marauder 9R/5S is massively easier to build, with fewer parts and better contact points. The Warhammer 7K has single-piece feet/legs/waist IIRC, and I think there's a Thud variant with fewer parts. So there is value in - not complaining, but letting IWM know there's a market for variants with fewer parts.
W.