On a Windows machine I can expect my relatives to install the software if I sent them the link to the download page. You'd think that installing simple stable software would be possible before you can talk about Linux usability?
You are actually saying that the windows system of installing apps is better than linux. The windows system(i mean the lack of one) is one of the main reasons Windows users get infected in the first place. Downloading software from unknown sources from the internet. All Linux distros have a central repository of trusted software with 2 or 3 clicks to install software.
I can't count the number of times I gave up on software install in Linux. Either it has to be compiled or it has a 100-item long list of dependencies
This is a lie, pure and simple, unless you are talking about LFS, all linux distros have a package-manager that resolve dependencies. There are the rare cases when you can't find a certain package on the package-manager and you have to install it manually. In this cases it's the software provider obligation to make it simple for your distro. All commercial software for linux have a simple way to install their app in the most popular distros.
Look at http://www.teamviewer.com/en/download/index.aspx for example. It has rpm's and debs. The install is simple and with one click in most systems.
I don't know where to start to list the things that just don't work in Linux. I really don't. I can typically resolve any problem that anyone in my Windows
That's because you are not a very bright person. OR/AND you are on the wrong line of business.You are possibly in a stage that can't learn anything different, so you reject everything that is different even if it's better.
GP is totally right. For a person who never used a computer, it find it easier to learn Linux desktop(of today, not 10 years ago) than windows. I find this true in my experiences because for all my relatives that I do free support.They all have Linux installed. Believe it or not the bothering ratio dropped enormously once I installed Linux, once they find out they could install apps with 1 or 2 clicks. I also recently migrated a small company to Linux(all desktops and servers) and there aren't any major adaptation problems.