Ok so you are saying people practising usury aka money lending aka charging interest are unable to love or be loved to the degree they would have been able to if they did something else. Ok.
So two parties agreeing to a contract, knowing its terms are reducing their capacity to love or be loved. Let me know if I'm twisting your words as this is the information I have distilled from your post.
I do not know if what you say is true or not as 'love' is difficult to quantify and furnish proof of. All I will say is that me and a lot of people on the dailypaul make their living and enrich other people's lives through this mechanism in ways that CAN be quantified without ever having felt this di.inished us in any way. That is my opinion.
Your post was reasonable and interesting that is why I replied, not because of any other reason.