Technical reasons aside, a fair bit of the lack of adoption seemed to be driven by the "it's not what I'm used to using" factor. As well as that you had a healthy serving of "my favourite platform's better than yours" mentality as well. While it's still very common these days, back then PC enthusiasts, (both corporate and private) would poo poo alternative platforms to theirs for no valid technical reasons. Many then, and sadly many still do, seek to engineer reasons (no matter how weak) for why people must use a particular platform (their personal choice).
While Commodore didn't produce the most effective marketing for corporate folk (to say the least), for people who think of themselves as gods gift to computer noobs, many IT people sure did make a point of ushering people away from and decrying the benefits of the other more advanced platforms until their own preferred platform had them as well, and then, boy, it was amusing to watch their new dog and pony show with them proclaiming just how fantastic GUI's and multi-tasking really were now.
Word processors, DTP packages, spreadsheets and databases were all there to be had for the alternative platforms. It was back then just as mandatory as it is now to have at least those bases covered for each and every platform. While there were some really good packages for MS DOS there were for the other platforms as well and when combined with those other platforms intrinsic benefits it really does make ya think. There was a decent emphasis on games and graphics titles for both the Atari and Amiga platforms around launch and through their lifetimes but they also strongly pushed the benefits for productivity of their GUIs environments not to mention pre-emptive multi-tasking for the Amiga.
There was a bit of a trajectory for an IBM and clone dominated industry being set even by 85 or 86 or so, but not to the extent that the newer platforms on a purely technical level would've been able to overcome in a neutral market place. The power of the FUD was as strong as ever during those days.
I should say though that if the IBM PC platform was a complete piece of junk it wouldn't of succeeded no matter how strong the lobbying, etc. It was at least a serviceable, and later quite a compelling platform. Just not always the most compelling available.