Riders cause good bills to be scuttled or changed in a bad way if the rider contains material that is basically contrary to the goals of the writers/sponsors of the bill. The use of riders should be outlawed.
When a bill goes through Congress to be ratified, it is legal to add a "rider". The stated purpose of riders that is taught in school is to speed up the process of passing bills by handling more than one at a time.
The truth is that riders are used to manipulate bill voting by forcing Congress to pass a good law with a bad one, or by throwing out both of them.
Thus Representatives and Congresspeople must choose between "the lesser of two evils" instead of voting based sheerly on the inherent value of the bill at hand.
In essence, this sort of "compromise" is robbing America.