Mainly because the encapsulating polymers are solids suspended in/by water and other solvents... Formulating in a liquid removes the step of boxing your solution for proper mixing & ploymer dispersion in the solution/emulsion & eliminates the possibilty of having a visible powdery residue from the fillers/base that the active ingredients are sprayed onto. Also the proper concentration of polymer could be an issue with a powdered product...
Try some Snake Oil side by side with a powdered encap product and see which resoils... I have every confidence that our product will not only put clean any product ounce for ounce but will hold up to traffic as well. If it doesn't I'll send you a gallon of your favorite competing encapsulation product on my own dime & buy your table a round of beers at the next Mikey
Fest.