I remember when Microsoft was fined for not offering other browsers to users: https://www.theguardian.com/technology/2013/mar/06/microsoft... . Chrome OS can not even install other borwsers by default, and it seems like nobody cares :/
We live in weird times when there is (almost) only one browser left... Chrome (chrome-clones). The argument may soon be moot regardless of market share or other variables.
(Of course, I'm stretching this a bit for effect but it's scary to think about).
I need MS to install IE, so I can use it to go and get IceWeasel, or whatever. Leave them alone!
Software was distributed offline as well. It seems like a long time ago now, but there was no shortage of AOL installation discs at the time.
(In fact, I believe both Internet Explorer and Netscape Navigator were distributed on floppy disks at one point, although that would have been long before the antitrust case.)
The world of 2001 was very rapidly becoming the connected world we're in now, and imposing a restriction on anyone like that now would just seem ludicrous and in fact user hostile, as it was. To me and I think anyone else paying attention back then, that was very obvious.