I have absolutely nothing against "love" marriages and they certainly can work. However, there is a much lower divorce rate in arranged marriages because what happens is you just kind of end up in a marriage with a person and then you work at it and eventually learn to love each other. Think of it this way- have you ever seen a hot girl or guy and wanted to date them but once you talked to them you realized that they were a terrible person? And have you ever seen a person who wasn't that good looking but once you got to know them you wanted to date them? That is exactly what happens in arranged marriages.
Another reason arranged marriages work better is because in most cultures with arranged marriages divorce is extremely frowned upon. This is not necessarily a positive thing but it does show that more arranged marriages last than "love" marriages.
We all have the capability inside of us to be with a person forever, but people in arranged marriages just tend to work at it harder.
A marriage should be between two people who truly love each other. People who have known each other for a long time, gotten to know each other etc. When you start forcing an arranged marriage, the chance that the two people haven't gotten the time to properly know each other increases significantly, making likely that the people don't actually love each other.