The thing that makes amends valuable is that you can tank from a non tank setup group with it(most of the time). While in general other tanks need a dire/coercer/swash/assassin to be as stable as a paladin with amends.
Its not like its hard for anyone thats worth a fuck playing any tank class to hold aggro. Don't act like paladins are the only class that can hold aggro and don't act like we have to use amends to do it.....