Poser was initially not meant to be used like it is now. It was more like Goo etc.: fun for kids.
I agree with you on the interface, but when you read here how people don't like anything to change (the forum, the site) then you know how the poser developers are stuck.
I want multiple undo, I want fully separate cameras and lights (not having to switch to adjust a camera and then switch back to that finger or eye, I want a search that stops when I click "no, dont continue", I want bum files to be ignored in the search, I want better joints, I want a separate folder for morphs and characters outside the pose folder,...but the developers have to take into account that most people will want backwards compatability...and prefer things not to change. They want that new sportscar, but it has to have the look and feel of their old bike.

This said: in most cases, subfolders are much handier than separate runtimes.
Just like using the material room to get your materials is perhaps a bit slower, but a ot handier when it comes to organisiation that pose files. Many (older ones) still include bum files, adress a wrong bump or (recent ones) simply have bump not attached to anything.

And: if you want to rename a runtime, it will not be recognised. You have to put it inside a folder called "old stuff", but the names runtime and its subfolders must be kept.

As an aside: Gongyla came home yesterday with a second hand book: New territories, the computer art of Jurgen Ziewe. They were made some ten years ago with KPT Bryce, FractalDesign Poser, Mandelzot 2, Strata studio pro, and this on a mac 8100  with 140MB ram and a 120MHz processor....

At the time, I didn't even have a puter and wasn't interested in one.
Today we drown in the sheer numbers of apps one "needs" and the puter one "needs" to be able to use them. But when I see what mr Ziewe achieved, naive as it may look today, I can only say: hats off! and stop whining.

I have tried prudent planning long enough. From now I'll be mad. (Rumi)