We've been down this road before. Associations and owners find the retrofitting distasteful. I don't believe the costs outweigh the benefits to the unit owners, since the chance of experiencing a loss is quite low and many people do have insurance, as required for their mortgage. 

I would say that the retrofitting is ironically not for the benefit of those non-sprinkled unit owners as many posters here seem to think, but more a benefit to tax payers who have to pony up firefighters, police, and other public resources to fix and investigate the issues. 

So if we as a community do agree generally that sprinklers should be in every building, then the retrofitting should absolutely be subsidized. In fact, I believe that's the only possible way to see this initiative through, given how unpopular it is with the associations.