In 1988, Lotus 1-2-3 held 70% of the spreadsheet market. WordPerfect ruled word processing. Microsoft's versions were also-rans. Within seven years, both leaders got sold off for parts and Office ran the desktop. Neither one lost a product battle. The interface underneath them changed. DOS gave way to Windows, WordPerfect bet its GUI effort on OS/2 and shipped its Windows version late and buggy, and Microsoft built native apps for the window it owned. Then it priced the kill shot. Office…