To your new questions:
1. Yes. As mentioned in previous posts, the drive of those behind Linux is not for business competition, but advocacy (for "software freedom").
2. In the article you have posted, and in practical terms, people refer to the OS when they say Linux.
Strictly speaking, however, Linux is not the OS itself. Linux is a kernel (a very important component of the OS) that was created by Linus Torvalds. While Linus Torvalds has the final say (being the creator of it), he technically contributed only 2% of the code of the Linux kernel. All Operating Systems have a kernel (it's the "heart" of an OS). MS Windows has a kernel too.
3. Linux is "difficult to use" due to installing hardware drivers, yes. But to be clear, Linux did not intend for it to be complex. Here's the reason why:
A computer is composed of different components (physical parts). Typically the major ones are:
a. motherboard
b. processor (Intel, AMD)
c. RAM (a.k.a. "memory")
d. Storage Device (hard drive, SSD)
e. Graphics Processor (a.k.a. "video card" - but you can go by not having this since most motherboards have the graphics processor integrated/built-in). If you are installing a separate graphics processor (a.k.a. "video card"), the most popular brands are NVIDIA and ATI (now owned by AMD).
f. LAN/Ethernet chip/port (yung saksakan ng Internet cable, for physical connections). Usually Realtek yan.
g. WLAN chip (yung "wifi"). The most popular brands are Broadcom, Atheros, and Ralink.
h. Sound card. Usually this is also built-in/integrated with the motherboard (and usually Realtek din ang manufacturer ng chip). Other enthusiasts install a separate video card (Creative, XFX, and Asus, to name a few).
Now, these components need to have "software" pa rin for them to be "recognized" as existent by the OS (a.k.a. "drivers").
The hardware manufacturers are the ones creating the drivers. Unfortunately, a lot of them don't share the source code for these drivers (proprietary, a.k.a. "closed source").
The "closed-source" nature of the drivers make it difficult for Linux developers to create "Linux versions" of these drivers a lot of times. There are attempts to create "open-source" drivers, as you may have noticed when you first install the Linux OS (for the video card, typically). But of course, these are not "as good" as the drivers that are created by the manufacturers themselves.
So, Linux developers are limited not by skill, but because of being "locked out" (they can't see the source code).
For the following items:
I would say that one "con" of making things "free" (for anyone to create his/her own "Linux" to his/her liking) is a "phenomenon" called "forking". In layman's terms, people/groups with differing opinions, direction, and advocacy will tend to split up and create their own mini-groups (hence the term "forking", or "fork" where, from a single handle, the metal pieces of a fork will "split" into four pieces).
Forking can bee seen as either good or bad (depending on who is looking at it). Amidst all the "forking", at the end of the day, the message of Linux is: "choice is good". Of course other people are not as adventurous and would like for things to "just work" and cannot be bothered with tinkering around (and this is not necessarily a bad thing).
As far as "too many contributors", I agree. That's why when choosing a Linux distro, users need to consider:
1. Level and scope of organizational support
2. Existence of a Governance Model
3. Structured "Quality Assurance" process
I stick to Ubuntu because there is a structured governance model and leadership group who steers their organization to a common direction (whatever direction is another topic, the point is there is a "steering committee" which governs the strategy/vision/direction of the group). I'm not saying that Canonical (the company behind Ubuntu) is perfect, but among all Linux Distros so far, Ubuntu as a Linux Distribution is well-managed.
The difference siguro of Ubuntu is that their founder (Mark Shuttleworth) is a very rich person who happens to be an advocate of FOSS, so meaning may "makinarya" siya (money). Ubuntu itself is free (as in walang bayad) - where Canonical earns money is through providing Training/Consultancy and Servers for Corporate needs.
OSX is also successful because there is a structured governance model, and a "steering committee" which gives direction to their organization (Steve Jobs during his time).
Other Linux Distros are heavily community-based so there is no governance model, steering committee, well-established Quality Control practices, etc. that is why their development is slow (compared to "mainstream" Operating Systems).
These other Linux Distros are maintained by people who just volunteer their time and effort, and without earning money for it.
But...if we remove that comparison versus "mainstream" Operating Systems...and considering all of the work was not funded - I would say that their work is impressive. As I said in one of my previous posts, reality of life is that people need to provide "food on the table" so given that, it means that these people who come up with various Linux Distros are really devoted.
As for "marketing": Linux is leading as far as "server computing". Most people are only seeing the "home computing" or "end-user" side of Linux.
Did you know that most social networking sites, email sites, Google search engine, banks, government, and (probably) even this forum site are hosted via Linux servers? Also in 2008, Steve Ballmer of Microsoft himself admitted that Linux leads 60% versus 40% of Microsoft when it comes to server computing:
http://en.wikipedia.org/wiki/Linux#Market_share_and_uptake
Also don't forget:
1. Android is an OS based on the Linux kernel.
2. IOS (the OS of Iphone) and OSX (the OS of Mac notebooks) are BSD
Android, IOS and OSX (which are based on BSD), and Linux are all "Unix-like" Operating systems.
