If I had to guess (without reading the case specifically), it's probably because Microsoft screwed up by forcing OEMs to not install netscape in order to crush them.
It's hard to differentiate 'crapware' from competition, particularly given the context where Microsoft had just leveraged their power over OEMs to crush a competitor.
This still sucks though, a better outcome for users would have been Microsoft being able to require the machines to sell with a clean OS and then allowing OEMs to install software for the user at their request (rather than the OEMs being able to bundle crap for kickbacks).
Somewhat related, apparently the netscape guys went to Redmond and hung up signs around Microsoft's campus mocking them for ignoring the internet. Legend has it Gates saw these and pivoted teams to IE with a focus on crushing Netscape.
Startup talk often discusses how most startups fail not due to competition, but because of internal collapse. Big companies can't compete, innovator's dilemma, etc. There's a lot of truth to that but this is a counter example (and others exist too).
Wildly stupid to antagonize the elephant that's focused on other things to direct all of their resources to destroying you.