That isn't the case though is it.
Firefox has roughly 10% market share of the browser market and that is increasing.
Even though IE and WMP are bundled with Windows you do not have to use them there are free alternatives, Firefox being the prime example.
Opera are also jumping on the anti Microsoft bandwagon when it comes to web browsers what they seem to conveniently forget is that Mozilla / Firefox seems to be flourishing under the same market.
Right, so Firefox, a superior product that is FREE only has a 10% market share and you don't see the problem?
Opera are a business and have a business model that relies on people paying for a license to use their products - rather than a bunch of enthusiasts like Mozilla. They can't get any market share because everyone uses IE, the development of which is subsidised by Windows licenses, and that's why they're a bit annoyed.