Two good reasons?
Well, Middlepath let's see -
Firstly the prevailing winds in ZRH are west and south - seldom north winds so strong that 34 or 32 would be required, so an ILS was never needed until the present situation. When needed (very rarely) then a circling was flown.
Secondly the approach from the north, although over hilly terrain is less problematic than the appproaches from the east or south.
So until the Teutonic (and, it has to be said lobbying from villages south of the Rhine) input no ILS was needed or envisaged for 28 or the other runways. Now, as mentioned above, it takes a long time to plan, measure, get permission for, order, install and evaluate an ILS. It also means a complete reorganisation of the airspace - holding areas, ATC training and coordination to incorporate it into an existing system.
So the impatient cutoff date imposed by the Germans quite simply didn't allow time to carry out the work.
Also, the people who live in areas previously far from aircraft noise don't take easily to the change, so you get inquiries lasting quite a time too. As a matter of fact, they are being overflown, even as the enquiries go on.
I was in the southern Black Forest a lot this wonderful summer - mainly by racing bike - and I saw quite a few ZRH inbound flights. I say saw, because I hardly heard anything. When you compare flights over 5000 ft clean and in idle thrust in approach with the racket you get with gear, flaps and thrust spun up at low height over the newly affected regions, there is no comparison.
Add to that Middlepath, that for most Schwarzwäldner ZRH is the home airport, I would say that your rant above about sharing the burden, is way out of line.