Games or selling to consumers is a totally different line of business than enterprise software which Japan lacks talent or incubation for. There is just no upward mobility and little regard for software profession.

Line was made by Korean engineers and owned by a Korean company.

i-Mode is interesting but seems like there were no strides to innovate further than running a server side HTML application to proxy off of but Japanese consumers are unique in that they will put with mediocre or annoying.

I personally blame Son Masayoshi's monopoly and his close mindedness, too much focus on maximizing profits rather than innovation.