I don't know where your quote is from, but trying to own the "default" web browser and tying it to your OS monopoly seems like a pretty great idea from a "making money" perspective, if perhaps not a legal or ethical one.
The ethical issue would be around making it technically harder for competitors to create a web browser. Eg, standard practice on mobile phones (which is worse than anything MS ever did and has always seemed fine to me).
As for legality, I'm not a lawyer and definitely not an antitrust one, but as I see it, an OS is almost by definition an amorphous collection of tools that users need to make proper use of their computer and nowadays I can't imagine an OS that doesn't come with a browser, so would argue that they were absolutely right in integrating it. If anything, I see much more merit in suing them for abusing their OS monopoly to go into the solitaire gaming space.
I remember paying for Netscape 4, and I remember the pile of steaming garbage I got when I did that.