Why does pvp in a large chunk of f2p and 1 p2p mmo have this:

Pot spam pvp-> Archlord, All the perfect world games currently released,
twelve sky 2 and 1, knight online, rohan to a limited extent, and Aion and a few more, Fiesta Online.

Can someone explain to me why that type of pvp is so wildy accepted?
It just seems so terrible and pointless.

The reason i bring this up is because i hit level 113 in twelve sky 2 and and me and a friend was like how much money have we used on pots and the answer was crazy.