Because that particular action is not made for love, nor reciprocated, it's pure lust and degeneracy, weakness and ugliness.
Of course it makes the Internet whore happy when you give her money, but you are nothing more than a pig to her (I would think of you as well if you did that), because you don't know how I am, you just want me for my body and your retard brain just concluded that by giving me money I would degrade myself to touch you, when I can milk all those paypigs by doing barely anything. That's her mentality, and someone enabling this is what I find pathetic.
I bet it would also make her happy if you transferred all your funds to her, and then set yourself on fire.
If you have a girlfriend/boyfriend and she/he loves you & actually wants to be with you, by all means give yourselves presents, that's cute & fun! On the other hand, that simpleton/coomer stuff that was mentioned is disgusting.
It's a fucking transaction due to mouth-drooling lust & weakness masquerading as something less repulsive, which is not, it's as degrading as it can be for the donor, but the fact that they like that as well, is what adds to the repulsiveness.