Until Linux gets to that point (same with installing any software), I don't think it will be viable in the desktop arena. Say what you will about Windows, but it sure is easy to use, and I can get **** done.
Linux in general is better with out of the box support than XP is, and in some cases can beat 7 for certain hardware configurations.
And package managers are one of the best things about Linux. Compared with Windows which has... nothing... Of course, people are like "HURR DURR COMMAND LINE LOLOLOL" and fail to appreciate that it's objectively better by just about any metric.
Specifically, let's say I want to install something onto Windows -
1) I open a web browser
2) I have to search for the site that has the software.
3) I have to search through the site to find it's download page (often a Heraklean feat)
4) Find wherever the right one for my version of Windows is and click on it and go through whatever other rigmarole to start the download.
5) Sit around, wait till it's downloaded.
6) Find wherever the thing threw my download and open it.
7) Go through UAC and onto the installer.
The installer requires me to go through several screens of banal nonsense that any normal person is going to pick the "Yeah whatever" option.
9) Sometime later it's done.
Linux -
1) Open a terminal.
2) [OPTIONAL] I run 'apt-cache search xyz' if I dont know the exact name of the software package I'm looking for.
3) Type 'sudo apt-get install zyx'
4) I enter my password and press y.
5) Without any further intervention it downloads and completes.
You were saying something about a certain OS needing a better software installation procedure?