When it comes to Linux, the three things that I hear the most are this:
1) Free! As in speech. Anything that is not free is bad or should be avoided if possible.
2) Spread it. We want everybody to use Linux.
3) If there's something wrong with the system, it's your fault. If you can't use it, that's your problem.
The second one is the most common in my opinion. However, the first and third seem to conflict with the second. First, how can it spread if everything is free? In a society where money is king, there must be money for it to gain market share. So therefore, not all software for it can be free. Sure, there are benevolent companies like Canonical or Google that will support the software, but for the mass market to move to it, more companies need to adopt it. This means closed-source and paying (gasp!).
The third one is rarer than the others, but it seems to be the most common one when dealing with open-source zealots. At least in my experience. I've brought up flaws like fragility and counter-intuitive features, but generally I get told to "rtfm" (Read The Fucking Manual) or that I broke it and if I had known what I was doing, it wouldn't have happened. Unfortunately the 99.8% of the world who isn't a Linux enthusiast (like myself) doesn't have time or desire to "rtfm" or learn how to not mess up their system. This is why the third ideal contradicts the second ideal. While Ubuntu and Fedora and other distributions (I want to try PCLinuxOS when I have time, so sometime next summer most likely) have made excellent strides in terms of usability, the majority of the programs are still mainly unusable due to too many options, lack of non-technical documentation, or some other reason.
So Linux enthusiasts, in order to spread the word you must first accept that proprietary software does have a place in the world (I love getting paid to code) and that some people don't understand the concept of a man page or config file.
Note: I do believe there will always be a place for a pain-in-the-ass Linux distribution for power-users (aka Gentoo), which is part of the appeal of Linux to many users. I'm not suggesting that these change, simply the ones that are attempting to reach out of GNU-land.