Because there is no sense in spending money that you dont have to. Money doesnt grow on trees. Maybe you have special trees. In that case send some this way. I cant help it if you (generalized you) have the extra money to spend. Not everyone else does. If you read instructions carefully there is no reason your animal should die. Of course people recommend you NOT buy this or that and say take it to the vet. Because everyone tries to get more money out of people. I use that bottle permethrin on my dogs and cats and cows and horses. Its the same ingredient so its stupid for anyone to say you shouldnt use that.