OS/2 may have been fine in the abstract, but set in the context of the time, it left a lot to be desired. Not only did it require a bunch of extra (expensive) memory, it also required new the purchase of new software to take advantage of that memory. (Otherwise it was just a hobbled version of DOS via the compat. box.)
Combine that with the $3K SDK cost and the deliberately incompatible PM, there were good reasons it was a hard sell.
One of the big fails of OS/2 was the IBM never had the desire that it would ran on any PC clone. They priorize doing something similar what does Apple with OSX on lesser degree. In other words, there was few drivers for hardware that wasn't on a PS/2 computer. Add to the mix the non cheap SDK...
Microsoft was responsible for licensing it to other OEMs back in OS/2 1.x. Of course, this was before MS turned the the OS/2 2.0 project into an entire fiasco that is now one of my favorite topics.
Combine that with the $3K SDK cost and the deliberately incompatible PM, there were good reasons it was a hard sell.