Well, these days that key business app most likely is available under Linux today. Moreover, you no longer need to know how to type in command, because Linux has gone full-tilt GUI. As ever, Linux remains free (or fairly cheap, if you're talking a commercially supported distro), and Microsoft is more expensive than ever.
Accordingly, you'd think more people would be adopting Linux than ever before. In terms of sheer numbers, they are. However, Linux isn't displacing Windows in any significant way and it's not going to dethrone Windows anytime soon.
As with all discussions of Linux versus Windows, one has to separate the desktop from the server. On the server side, Linux is and will remain an operating system with serious market share. My argumentative question as to why Linux can't gain share beyond the very low single digits pertains to the desktop.
I'm not sure I have the complete answer to that one, but the first-cut response is, a) because Windows is good, or, more precisely, good enough, and 2) because Linux still doesn't deliver the complete ease of use that it promises. Let me clarify: Once Linux is up and running, it does give good ease of use. However, getting to that point, and maintaining the installation, is a task no less trivial than it is for Windows.
Hence, Linux's perceived advantages evaporates in the face of the finding that it does indeed require grown-up care and feeding.
Here's a comment on ease of installation:
"I have been sold on Linux for years, But let's face it, until you can install any Linux, on standard off the shelf commodity hardware you get from Best Buy, without having to manually configure additional drivers for the network card, media readers, etc., Well, as a consumer desktop, it ain't going to fly! I use Linux for servers, and development workstations, and love it! But I have to run windows on my laptop because when I get home at night, I don't want to have to hack my OS to get it to do what I want it to. The day will come when Linux will be there but that time is not now."
Here's one on the need to know what you're getting into:
"I do agree Ubuntu (and perhaps Linux) in general is not as intuitive as Windows (and perhaps it is not meant to be). One has to be ready to install additional software (e.g. C compiler) to install applications (for me it was Latex). There is definitely a learning curve and one has to be ready for it."
This correspondent makes a good point about Ubuntu's supporters being a little less "Linux like" than fans of other distros:
"Linux is nowhere [near] ready for the typical home user in my book. I finally managed to get Ubuntu running on my XP after much failure. Only took a couple of hours searching through the forums to find a possible solution. I will say the install process has approved over the last several times I have tried using Linux (Red Hat and SUSE). I will also say that the Ubuntu people seem more tolerate of newbies than from my previous experiences."
In my myopia, I never even thought of a point which at least three commenters made quite eloquently: Namely, that anybody who's attempting installs is already one step removed from the typical user.
"In my experience, only a small fraction of users are comfortable installing an OS. For example, I work at a scientific research facility crawling with PhDs. There's maybe one or two people out of almost 100 staff that will attempt even a plain Windows install by themselves. I imagine that in a typical business environment the ratio has got to be lower- and let's not even get started on the home market. The vast majority of people just use the OS as pre-installed when delivered. That's what makes the Dell-Ubuntu deal so significant."
"I won't recommend that any common computer user try to install any operating system, Windows or Linux. Proper installation of an OS should be done by someone who knows what he or she is doing whether you're dealing with Windows or Linux. Anyone who's had trouble "upgrading" a Windows operating system please raise your hands. I quit Windows upgrades years ago; easier to buy a new computer with latest operating system installed at the factory. That's why people are excited that Dell is selling systems with Linux installed already."
"Whenever you start talking about installing an OS, you are no longer talking about the typical user. The typical user buys a machine with an OS, or brings it to a dealers/Geek squad when there's a problem. I've personally experienced nightmarish problems trying to get retail versions of Windows XP installed on machines once the OEM CDs were lost or damaged. Anecdotal installation stories are fun to read, but they don't apply to the majority. Pre-installs are essential to reach that market."
Here's my favorite comment; not necessarily because I understand it, but because I love the puppy analogy.
"My experience installing Ubuntu proved to me that free software is like a free puppy! After many hours I was able to successfully install Ubuntu. Was it worth it? Like with a puppy you don't really know until it grows up. As for now I prefer to stick with the tried and true XP so I can focus on work rather than raising a puppy."