Those with short memories tend to believe what executives from cable firms tell them, and this week there was the repeat of an earlier forecast from New Street Research, which said all the US cable giants would all drop their capex over the coming year or years and so will many in Europe. It is true that their spend currently – especially the highly visible public big three, Comcast, Charter and Altice – has been inflated by the rollout of DOCSIS 3.1, and that this was far higher than had initially been expected. DOCSIS 3.1 was introduced around 2013 as 10 Gbps up and 2 Gbps down technology compared to what had turned out to be the 100 Mbps up…