Well put.

The hot water serves to take all the THC acid and Decarboxylize it (knock a COOH off the end of the molecule) to convert it into its psychoactive form. If you were to just make the tea, it might knock off some converted THC in suspension, but nothing would dissolve. However, if you boil the weed for a while, drink the water, and then eat the weed paste left over (or mix it with sugar and put it on a cracker, whatever), you'd prob get hella fucked.