I have 8 GB of memory on my Macbook Pro, and I've never seen anything like the problems described in this article. I leave my machine up for weeks at a time, I leave the Time Machine drive connected for weeks, and never have a slowdown, even when time machine is backing up.
The only time I have memory issues is when I have too many safari tabs open for too long. Eventually safari takes too much memory. So, I shut down safari and start it back up-- it opens up all the tabs that were open and takes a lot less memory.
I'm kinda astounded that people with 20 and 32GB of RAM and 8 CPUS are saying it takes 5 seconds to open a terminal window. Have never seen anything like that.
I would venture to guess that these people who are seeing the problem are running a kernel extension or possibly have otherwise modified their machine.
Whether you use Windows or OSX (or both, as is my case) you can probably rattle off a sizable list of how these OS's have gotten screwed-up by their respective publishers. Someone saying "<OS name> is wonderful" and then going on about the reason it actually isn't is very funny.
Again, the comment was OS agnostic even though the thread is about OSX.