I guess because, as the article describes, IBM was all for protecting its workstation business as well as the lucrative mainframe business.
A workstation back then was defined as an expensive high-end computer that was designed to be used by only one user at a time (i.e. not a multi-user mainframe), yet was suitable for high-performance applications. They were intended mostly for corporations and academia where extra juice was needed and that could afford to buy workstations (think scientific computing, CAD and graphic design in the 1980s). IBM did at this time already manufacture workstations with UNIX as the operating system (see e.g. http://www.old-computers.com/museum/computer.asp?c=867&st=1 ) But they were way too expensive for the home user. PC (personal computer) was the low-end product that you could afford with a normal salary.
I understand UNIX back then was a mainframe and workstation operating system. Licensing was expensive and the hardware requirements beyond that of a PC. Few people had access to UNIX, mostly at universities and at big corporations. These were the very reasons why GNU and Linux were born - to provide a mostly-compatible UNIX clone for the home users with an affordable IBM PC compatible.
So my theory is that IBM was protecting its mainframe business - it did not want to put the powerful UNIX to the PC because it wanted to sell more expensive special hardware to those who wanted UNIX. So it hired a maverick company (Microsoft) to write a low-end, feature-poor operating system for PC (DOS). It was (and continues to be) a business strategy to bundle better software with better hardware so that you can ask customers that want only the superior software for a higher price (still essentially the business model of a certain Cupertino, California based manufacturer)
A workstation back then was defined as an expensive high-end computer that was designed to be used by only one user at a time (i.e. not a multi-user mainframe), yet was suitable for high-performance applications. They were intended mostly for corporations and academia where extra juice was needed and that could afford to buy workstations (think scientific computing, CAD and graphic design in the 1980s). IBM did at this time already manufacture workstations with UNIX as the operating system (see e.g. http://www.old-computers.com/museum/computer.asp?c=867&st=1 ) But they were way too expensive for the home user. PC (personal computer) was the low-end product that you could afford with a normal salary.
I understand UNIX back then was a mainframe and workstation operating system. Licensing was expensive and the hardware requirements beyond that of a PC. Few people had access to UNIX, mostly at universities and at big corporations. These were the very reasons why GNU and Linux were born - to provide a mostly-compatible UNIX clone for the home users with an affordable IBM PC compatible.
So my theory is that IBM was protecting its mainframe business - it did not want to put the powerful UNIX to the PC because it wanted to sell more expensive special hardware to those who wanted UNIX. So it hired a maverick company (Microsoft) to write a low-end, feature-poor operating system for PC (DOS). It was (and continues to be) a business strategy to bundle better software with better hardware so that you can ask customers that want only the superior software for a higher price (still essentially the business model of a certain Cupertino, California based manufacturer)