One reason: stigma.

All I recall from childhood/teen years is "IBM compatible PC" a mantra on every TV commercial IBM or others produced.

A PC was for business and you were rich or a fool to spend thousands on something so useless to a regular Joe.

Apple was even more expensive and even less common than a PC and even so Apple was quirky and drew pictures, ATARI and Commodore were for games.

They were in totally different worlds. Back then I wouldn't have even thought to have one computer that did everything.