That powerful IBM system was unique to other systems being brought into Japan, in that IBM started up that business just before the rule that required a Japanese partner. So it didn't really get shared like other technologies that lead to most other Japanese tech giants.
DOS/V was just PC-DOS with some additional device drivers. IBM licensed it to Microsoft who in turn licensed it to other vendors such as Toshiba, Sharp, AST, Compaq, Dell and Fujitsu.
The biggest barrier to its adoption was vendors such as NEC (with their PC9800 series) and the AX consortium (Oki, Casio, Canon, Sanyo, Sharp, Hitachi, Mitsubishi) who had already invested in proprietary hardware for Kanji support and were threatened by the support of Japanese text on global standard hardware. (That said, some AX vendors decided to embrace DOS/V anyway, such as Sharp.)
Another barrier was that DOS/V had different APIs from those previous solutions so you needed new software that could support it.
