When you apply a gift to a recurring gift or pledge, typically it copies a lot of fields from the original gift. This is often sloppy.
For instance -- a recurring gift is made online. It is then marked as "receipted" because it was. But now each payment is marked a receipted when the payments are applied. The payment then has to be manually fixed each time. I don't want to set the original gift as not receipted because that isn't accurate.
I also have issues with the letter assigned to these gifts. A pledge will get a pledge acknowledgement letter, but that isn't the letter that the gift should get. It has to be manually changed.