This is because US fines are laughable. Try Microsoft paying over Billion dollars for IE bundling in EU. The way things are going they are due for another round or billion dollar fines soon.
Does ANY for pay OS today not come with a Browser? How the hell else am I supposed to get a Browser without some form of browser? Go to the store and buy one?
Yeah, boo IE, hiss Microsoft, but honestly including core functionality like HTML rendering in your operating system is not morally wrong.
They then managed to not ship this selection screen for a year or so on Windows setup disks and ISOs. Hence they got the $1b fine.
Although to be fair, they cheated the original developers of IE out of their money, too, by promising them a cut of the sales on IE (which they had absolutely no intention of delivering, seeing as they planned to give it away for free), so it wasn't quite "at a loss".
This is kind of a weird claim. They gave Notepad and Solitaire away too. But they weren't giving any of that away at a loss; the "at a loss" concept doesn't even apply to software sales.
The wheels of justice turn slowly, but back in 1994 or so when this all happened, people did go to the store and buy netscape navigator on disk or CD-ROM.
For the historical record:
ftp ftp.mozilla.org
cd pub/firefox/releases/