Softbank of Japan has been held up as a shining example of how a visionary leader could help an operator diversify beyond the increasingly pressurized business of mobile and web services. Chairman Masayoshi Son has famously set up the massive Vision Fund and invested in companies in many countries and many areas of the hi-tech value chain, with a view to playing in most of the key enablers of next generation digital services, from chips to artificial intelligence. However, telcos can be over-ambitious when they seek to move out of their comfort zones, and two high profile Softbank investments – in ride sharing firm Uber and shared workspace provider WeWork – have caused a disastrous set of quarterly results for…