Robert R. Paddock, thanks.

Do sprinklers significantly reduce property damage from fires in highrises?  Do sprinklers actually save lives or injuries?  

The most objective way to find out is to look at the premiums charged by companies for insurance policies for owners or renters.  If there's any difference in premiums between sprinklered and sprinkerless highrises, that difference would be an objective measure of how much value professional actuaries place on sprinklers.  

Insurance companies put their money where their mouth is.  They study how much was actually paid for property damage and loss of life, and adjust the premiums accordingly for future years.  I'll bet there's no difference.  Or if there is any difference in fire insurance premiums, compare the total difference in premiums over 30 years against the cost of retrofitting.  

Then there's the cost of moving out people and their furniture to let sprinkler pipes be installed. And the cost of asbestos removal.