Why is Ubuntu shipped with firefox?

I'm just curious, and some of my friends too. Personally I think "chromium-browser" is better (faster, less crashing) than "firefox", and, why Ubuntu not shipped with more than 1 web browser?

From an interview in 2011:

Canonical founder Mark Shuttleworth is a big fan of Google Chrome, and says the browser could replace the standard Firefox in future versions of Ubuntu Linux. <..>

<..>In fact, Shuttleworth says, "We looked at it closely in the last cycle and the decision was to stick with Firefox in 11.10."

11.10 is the next version of Ubuntu, to be released in October as part of Canonical's twice-a-year release cycle. Chrome probably won't replace Firefox in 12.04, due out in April 2012, either, because that will be the long-term support version, making it an unlikely candidate for major changes.

"That probably keeps us on Firefox for another year, at least, and we'll see from there," Shuttleworth said.

If that sounds like a wishy-washy answer, Shuttleworth also made it clear that he is a believer in the future of Chrome on Linux.

The work Google is doing with the Chrome operating system, which runs the Chrome browser on top of a generic version of Linux, "is having a hugely positive impact on the performance of Chrome on Linux," Shuttleworth said.

So... it is up for discussion (as are all other default packages) with every release that is not LTS. This time around Firefox wins. Maybe next release it will be Chromium.

Why Ubuntu not shipped with more than 1 web browser.

Ubuntu ships with at least 10 browsers: you can find them in Ubuntu Software Center. There is of course only 1 default browser and as such only 1 is installed directly. In our case Firefox but you are seconds away from installing another one.

There's no reason to come with more than one browser pre-installed as that will just take up more space on any installation media. It isn't difficult to download a variety of others one everything is installed.

As for why Firefox, I would say that the ethics of Firefox as a open source web browser match more with Ubuntu than that of the Google sponsored Chrome or it's open sourced experimental arm with Chromium.