Why does Firefox impose Google as a search engine in it's home page?

Mozilla happens to receive a hell of a lot of revenue each year from Google, for having the Google / Firefox homepage as the default. That revenue stream makes it possible to give you a web browser and other services at no charge.

Are you aware that you can set any web page that you want as your homepage? Which hardly makes it an imposition.

http://support.mozilla.com/en-US/kb/How+to+set+the+home+page

I've found Firefox to be very unstable when it comes to choosing a different home page & search engine, frequently ignoring my choices & reverting to the default settings between launches. This also applies to Google & the choice of language if it's different to that of the country the person's in, which is my main gripe with Google, it doesn't detect the language of the operating system but that of the geographical location, forcing one to alter the settings every time, which is extremely annoying! Please do something about all this if possible, thanks.