It's not even about single-part minis. Smaller part numbers can give great results. I'll highlight the Reseen Archer (with the very notable exception of it's finicky missile bay doors.) One piece feet/legs/hips in a dynamic walking pose, torso which can be put on swivelled to left or right, and two single piece arms that can be put on as desired, even bent more or less simply.
I don't know many people who favour the old "standing at attention" pose of some of the old minis.
The new plastic minis have really done great work in providing dynamic poses that most people don't bother changing, effectively single piece (although I'd do some significant maiming to get hold of unassembled plastics, that dream ain't likely to fly, and it's so easy to mod the plastics if one feels inspired to do so.)
It's all about maximising the number of people who can get minis on the table with - for them - acceptable levels of investment of time & energy. The 'master class' multi-parts of the early Catalyst era hit the spot for the dedicated enthusiasts who are prepared to invest the time & effort - what percentage of players and potential buyers are these? 5%? 3%? I'd love to know.
Another case in point the Scylla. Hands up those who gave up trying to get the individual fingers on?
Would a two-part arm - everything except the missile plate & fingers, and a single-piece 'crown' with the missile plate & fingers - been possible?
So no, not arguing for single-piece. Just welcoming & valuing the efforts of Crackerb0x & our other sculptors
Doing things like providing solid connection points that are keyed (and the keys can be removed if people want for additional poses) or providing built-in pins when connections are suspect have been something I've been trying to include whenever possible.
And requesting they consider the mass-market implications of going massively multi-piece.