The short answer is 'public demand' !
The slightly longer answer.......
Way, way, back when it was first introduced, water was in fact dry and In that form it caused no end of problems. For example, the death rate of pet goldfish went through the roof and washing your car on a Sunday morning would literally take the paint off the bodywork. However, most seriously of all, people were having to chew through their morning coffee!!! This of course made them late for work which impacted not only on their take home pay but on productivity in general. As a consequence, apart from the boom in goldfish burial services and car re-sprays the economy descended into deep doo-doo's and times were tough. This was especially true for the working classes who were forced to exist on little more than dry bread and dry water. Not unsurprisingly, this lead to mass protest marches, name calling and the withholding of taxes. Eventually, the government took notice and realised that trying to do things 'on the cheap' by introducing dry water, had backfired. So it was that in the September of 1356 they raised the 'Wet Water Bill' which basically lead the way to water being what it is we know and take for granted, today.
I notice that death rate amongst pet goldfish is on the rise again. Anyone know what might be behind that?