And yet there is room to grow. When Microsoft peaked, they had almost achieved a monopoly-sized market share. Apple on the other hand has managed to grow this large despite their most successful product having a minority market share. It is both impressive and just a little bit scary.
I read your comment as implying that Apple's potential to swallow the world by increasing in size is scary. The other way of looking at it, if you're an Apple investor: Apple's lack of a "moat" is scary.
Because MS decided virtual growth was the way forward (well... they decided it by releases shitty services and products horizontally) and Apple decided to focus almost entirely on horizontal multi-product approach to growth. The latter will always win long term.
