As you've brought up the topic of OS/2 then I feel entitled to re-open "OS-wars" and deal with the comment in the article
"Presumably if you spent all day trying to slap a GUI interface onto Windows 3.0 ..."
... ermm - Windows 3.0 was a GUI that was slapped onto MS-DOS - it wasn't a proper OS like OS/2.
Thank you, I feel better for saying that!