please explain?

I live about ten minutes jogging distance from a lovely man made lake. It is a beautiful place and very popular with us joggers and dog walkers and cyclists, and mums and dads with babies, and friends going for a stroll......you get the picture. Recently some new units have been built directly opposite part of this lake. 
Oh lucky people who are getting to live with our lake as their front yard!!


This is the lake from where these new units have been built :

pretty isn't it.

Now these new units are going to be people's homes so I won't say much about the 'we've got to house the masses' communist era chic nature of the architecture. The front blocks of units (there are a lot of them) are only a couple of stories high :

The bit I really don't get is this. Those murky, poo brown, head height cement rendered walls are in front of glass doors that overlook this :

Look closer, it's true.

Why would anyone plan to block out a calm, beautiful, spirit lifting and probably reasonably expensive view (which sometimes has ducks and swans in it!) with such an er, odd, wall? I really don't get it. Privacy? Hello, curtains!

Is there a rational reason for this design element?