General update manager

As a computer user migrating from (mainly, but also other linux distros) Ubuntu to Mac OS X, I have come to love many things about OS X and Apple over Ubuntu and Linux, but two things for me remains as killer-features that OS X has nothing of that comes even close to what Ubuntu and Linux has.

The first thing, which is what I will target in this thread, is an general update manager, like the one Ubuntu has in Update Manager app that takes care of keeping everything on the system up-to-date, also third-party apps. The second is a general notification scheme, where almost all OS X users are settling with the third-party app Growl.

But back to the main issue of this thread, the none existing general update manager for OS X. Why isn't there one? Apple hits user-friendliness in every single corner of OS X except this one, which I think is one of the most important ones.
I can see why it would take time to get such feature implemented, but by making it easy for third-party developers to "add" their application to the manager, by defining some general way of releasing the software, Apple could put the press upon the developers, and not themselves, and would have made a great addition for their desktop operating system, only for them to sit back and thrive upon, while the third-party developers would be busy getting their apps to work with the General Update Manager.

Why is this not done yet? Why? It has been in Linux distros for ages, and is, in my opinion, an important system feature along others like a window manager, maybe even the kernel. By not providing such a feature for their system, they are sort of alienating the third-party applications, by not giving them the ability to link in with the wholeness of Mac OS X such as Apples own applications does in the existing Apple-apps-only update manager.

What are your take on this?

Cheers guys, have a good night.

 

I was also trying to get a debate going on the topic. Anyhow,

@miles01110:
It seems to me that you have never used a system with an Update manager that takes care of keeping all things on your system up-to-date. (maybe you have, I don't know) but the neatness of this is number one) that you achieve more with less effort, meaning that the system doesn't have 20 different update managers running and checking for updates all the time and hogging resources, instead it has one. Also, some apps, many apps, don't have these separated processes that runs once in a while, some only check when the app are running, so you can miss out on updates for a long time because you don't launch the app and then one day you have no Internet connection and you launch app and don't get the update.
Okay, number one reason was the best. Also because it should not be the third-party developers job to take care of maintaining an update utility for their apps. The apps resides inside the comfort of the OS, so it is the OS that should take care of it's residents.

@HikariYuki:
I know about those. And the idea of bringing something to OS X that is hurtfully missing is great, but where e.g. Growl succeeds, these Update Managers fails, because the apps don't use a common scheme for releasing updates, so it's impossible to do the job in a good way, which all the third-party update managers I've tried are prove of.