The problem with the installer is not so much that it's unstable, but that providing a GUI installation routine removes what used to be a VERY efficient filter to new users. If you are going to use Gentoo, you MUST be comfortable with a command line. You MUST be able to read instructions, understand them, and adapt them. The manual installation process will inevitably discourage people who fail on either or both of the above. A GUI installer removes that filter, meaning you get more people using Gentoo who really would be better served with a different distro, not because the other distro is easier, but because the other distro is better suited to their needs and desires.
Now, is this elitist? Possibly, but I don't think so, at least not inherently. Different people have different needs, and different levels of ability. There is no "One size fits all" solution. To try and impose such a solution is even more arrogant and offensive than saying that some people will fail. I can't play football as well as Christiano Ronaldo, so Manchester United are being elitist for not signing me? I can't use a command line, so Gentoo are being elitist for suggesting I use a distro that can be managed through a GUI? Funny how only the second is elitist!
As someone who has spent time in #gentoo trying to help new people on IRC, I take serious offence with being accused of elitism. I, and several other people, have spent hours trying to explain how gentoo works, how to install it to people. In many cases, a huge number of installation problems are solved by telling people to stop using the GUI installer, and just let us talk them through a manual install. And you know what? Those who can do that succeed, and are normally very happy with the result. Those who can't? Realistically, they should not be using Gentoo.
Now that is not to say that Gentoo does not have elitist users, it does. But that is simply a result of being a quite technical distro. Just like it also has more than it's share of "performance" nutters who "tune" their system into instability. To get a fair view of the environment in Gentoo, you need to spend a little time experiencing it. I do not think you will find many people who have been in the Gentoo community for long who would say that it is elitist, or unwelcoming to new people. Just that it expects certain things of users, like an ability to use a command line, and to think.