What? It is not a suffer to seat a middle seat in business class??

If this is not a suffer, then why many airlines, like Virgin Atlantic, US Airways, Air Canada, LanChile, advertise their no middle seat business class service?

This proves middle seat is NOT welcomed in business class.

In fact Air Canada and Virgin Atlantic once ordered B777, but cancelled because B777 is so wide that 7 seats have to be installed per row in business class, thus making some passengers have to suffer middle seat. B747, on the contrary, has the front cabin so no middle seat can be installed.