What are you talking about? Maybe you just dug up this old discussion with a obvious Switcher that wanted OS X be just like his Old Windows box not realizing that in OS X developers regulate if their application will have seperate sound controls. If their game doesn't have seperate control then critique the developer, not Apple.
Besides if someone wants better OS X sound control should look at the shareware
Audio Hijack Pro.
Alright, being a Windows and Mac user, and loving both of them, i do understand the advantages of having a Mixer.
I have taken the liberty of adding this screenshot for you, that should help me in making you understand the advantages we talk about. As you don't seem to understand what Unhyper meant.
Now lets take a look at this from my point of view.
I am the kind of guy who enjoys listening to his music with a set of 5.1 surround speakers, and i do love it loud. Now nothing disrupts the moment of pure awesome, as a painfully loud "PLING" sound notification from Steam/Skype/Facebook. So how do you fix that? On windows it is quite easy, open the mixer from your volume icon, and simply reduce the volume of the target application in this case Steam.
Lets try the same on mac, still the same guy, still the very same loud and beautiful music making my day. It so happens that people still talk to me, and I get the very same incredibly loud "PLING" disrupting the moment. Now what do I do to fix it? Right, Volume mixer, and. It doesn't exist. Huh, so whats next? Check out Steam/Skype/Facebook settings, but it so happens they don't have a volume rocker for set noise, and disabling it entirely wouldn't serve me very well, as I do enjoy the notification sound getting my attention. I just don't enjoy it tearing my ears to pieces.
Now you might ask yourself why I added the Witcher 2 screenshot, Simple. To show you, YOU can have both, and you should. As we can see, the volume from Witcher 2 (30-50%) is not controlled by the Mixer in Windows (100%). Bottom line being, the developer does not lose any control over their applications. Windows simply adds or subtracts "dB" accordingly, just after the game sent it and just before it finally reaches your speakers. And paying a whooping 32$ for something that only does mixing as a side thing is stupid. And i would therefore go with "SoundBunny" instead, but even that one still is 9.99$ which if you take it into context is quite a loot compared to the Windows mixer costing absolutely nothing and being default. Besides, I quite like to have my Mac be pristine and i'd rather not have too many 3rd party softwares messing with my sound. I'll just go ahead and say, I'm not a fan of it. But if essential things are missing, you gotta fill it yourself.
Best Solution I know:
http://www.prosofteng.com/products/soundbunny_awards.php
Cheers!