For new build it's a completely stupid idea. And the more this crap comes to the surface, the easier it will be for developers and housing associations to wriggle off the hook. Cyclopathic is absolutely right - people want their bikes as close to their dwellings as possible, and, preferably inside.
1. Come one, come all. Unless you subdivide the pens with steel mesh, any one of the five people with a key can get in, and, more to the point, somebody'd going to leave it open
2. So......why not individual cycle pens? Because the usage ratio is rubbish, and the solid sided stainless steel ones are great for storing coke. (When one housing association removed a pen, the owners came round the next day and asked for £150,000).
3. The only sensible answer is to design the buildings around bikes - and, when you think about it, that's not so very difficult. A '13 person' lift instead of a ten person lift. Bigger hallways in the flats. Which (surprise, surprise) means that people can take up prams, those little electric mobility scooters and shopping trolleys to their flats. And, again, that doesn't take a lot of extra space - just a bit of thought when planning.