I used to live on the Isle of Dogs - just down and to the left from the intro photo on that article - on the Thames waterfront, albeit in a relatively modern 15-storey, multi-building estate.

I was always torn between wanting more access along the waterway edges - it would make a fantastic bicycle route into town, as well as further outwards - and wanting more privacy / protection from the kinds of idiots that thought partying in front of a residential building at 3am was acceptable behaviour. By partying I mean music, shouting, glass bottles being smashed, and so on.

The estate was in on-going 'discussions' over the previous several years with the local council about gating half the street, and consequently access to the foreshore. It was moot in terms of providing east-west access, as estates left and right had already gated their access. And it's clear this is one of the problems being described in the article - the 'let's make it less appealing so you want to _use_ it less so you can _lose_ it more easily'.

I'm back in Australia now, where I believe (IANAL and the information may be apocryphal) access to all tidal foreshore up to some distance, I think 30 metres? - was provided by law with two notable (military) exceptions. Whether that's the case or not doesn't affect the fact that it's practically impossible to obtain public access to foreshore areas in and around our capital cities.