selective sync on ipad?

If selective folder sync was an unique concept then I would understand the resistance from Dropbox. But this feature already exists on Dropbox for Windows, OS X and Linux variants. The constant re-phrasing of the same, canned responses and rewording the same question doesn't give us much hope that anyone is actually listening.

It seems that what most of the users here are asking is for same exact feature that's available on PC; selective folder sync.

We just want to be able to choose what folders get synced to the mobile device.

"Secure the app with a passcode in Settings."
That still doesn't enable selective folder sync. Setting a passcode will only lock people out from accessing the app, it does not enable organization.

Let's say I have a Dropbox account on three devices; my Macbook, my daughter's phone and my wife's iPad. We all sync photos that Dropbox grabs from the camera/gallery/downloads/etc.
I also store lots of drawings, documents and photos from my work. And my wife and daughter use Dropbox for school and hobbies. I don't need to lock them out, they're all responsible adults.

We all use the same Dropbox Pro account because we have lot's of storage and is very convenient. My wife and daughter don't need (or want) to see my work files. I don't really care what things my daughter and wife save to their folders. Now, on my Macbook, I can simply uncheck the files I don't want synced and they won't show up. The problem is Dropbox on our mobile devices.
My daughter is always saving and deleting her school work or photos of her friends, etc...add in all of my work files and personal backups that I constantly update, and now Dropbox on mobile is extremely cluttered.
None of us would deliberately delete each other's files but because there is no way to organize the mess, it's just always a possibility.

I use a Dropbox Pro account with some of my colleges. We use a passcode on all our devices that have a Dropbox account but that is only to keep unwanted users out. We need to be able to pull up Dropbox and go directly to the information we need to, in any given moment. We don't really have the time to stand around with a customer for several minutes saying "just a few more minutes sir". Our customers are not as patient as yours Dropbox.