I think the apparent contradictions here can be explained quite easily: Apple cared about design, and Microsoft did not.
Looking back from an era in which Apple's sensibility has prevailed, it's quite hard to explain the extent to which Microsoft, at least until the late '90s, really didn't care whether their software looked good. They genuinely didn't see it as important.
Well, Microsoft did hire Susan Kare to design the Windows 3 icons. Kare previously and famously did a lot of early Macintosh GUI design work for Apple. But while Apple saw GUI design as a holistic effort, at Microsoft, the good stuff (e.g. Kare's icons) and the bad stuff (e.g. the sloppily designed mouse cursor) just went hand in hand. Which adds to your point.
Looking back from an era in which Apple's sensibility has prevailed, it's quite hard to explain the extent to which Microsoft, at least until the late '90s, really didn't care whether their software looked good. They genuinely didn't see it as important.