For me, the thing that made MSX fail was over-standardisation - it was very difficult for manufacturers to stand out from the pack. Often, the machines all felt the same, so consumers would buy the machines on the basis of style - and there were some truly atrociously ugly MSX machines being designed in those days. (In some ways, its quite similar to the situation with, say, Android today.)
And then, there were the places where standardisation hadn't quite worked. Subtle differences between systems often mean that developers had to have a fleet of MSX machines to test on, to be sure. (Again: Android)
And in the midst of all of this, along comes IBM and the rest is history .. but for a while, MSX (and MSX2) were really intriguing technologies. Working on MSX in Japan led me to becoming an ITRON adherent, which led to me becoming a systems/OS developer.
https://en.wikipedia.org/wiki/TRON_project
.. which put me in the right place, at the right time, to become an early Linux adopter ..