Butterfly Bush and Neglect?

There has been some debate in the media about whether the Butterfly bush (Buddleja davidii) is rarely seen in London as land is too expensive to become truly derelict (https://www.theguardian.com/environment/2019/apr/05/the-butterfly-bush-thrives-in-london). Others have pointed out that this shrub thrives in London especially along railway tracks. The bush is actually very common throughout the UK and is yet another example of an alien species introduced by gardeners that has spread to parks and waste land. Buddleja propagates effectively on to any available areas but is by no means as problematic as Japanese knotweed or Himalayan balsam.