I can understand the comments criticising the rider for being too fast, too aggressive, not sharing the space etc. In an ideal environment it's quite easy for cyclists and pedestrians to share space. The problem is that this is far from the ideal environment for either.
The problem in Southend "Cycle Town", from what I have seen and know, is that these inadequate cycle lanes have been introduced in a way that makes it difficult for cycle users to continue to use the road without harassment. So, while they might be fine for someone who wants to potter along the seafront from Chalkwell to the Kursaal on a sunday morning, they are not suitable for someone who simply wants to get from west of Southend to east of Southend by bike along the shortest and flattest route.
The upshot is a collection of useless measures that make life more hazardous and inconvenient for cycle users. So much for "Southend Cycle Town".