Why people like paying for extra retainers as well as other stuff:

1) Many players don't have time to play games so getting any extra advantage is good.

2) Many players don't enjoy farming/grinding for loot (even though that's what mmos are usually about) So anything that takes away grinding or makes game life easier is good.

3) RMT is big business because players like to get things without having to farm/grind.


So really there's nothing you can do about the cash shops and small pay for advantages because there's just really too big of a demand for it.