...(P)eople want their Paladin to be able to do any damn thing they want, but don't then want to have to deal with the problem of their character no longer being a Paladin. Essentially, it's a form of powergaming.
I've participated in- and started- enough Paladin threads to recognize the truth of this.
OTOH, I've also stated that there are basically 2 different but not mutually exclusive kinds of (LG) Paladins, and a lot of tension develops when the Player and the DM aren't in agreement as to how to play one. Those types I labeled "Old Testament" and "New Testament," because their differing moral compasses are directly mirrored by that particular ethical breakpoint in the Bible. (You may substitute other terminology as you see fit.)
The "Old Testament" types are called by their god to be judge, jury and executioner, wiping out all evil without mercy or hesitation. Evil is to be utterly eradicated. In extreme cases, they may even slay those evildoers who surrender, because it is up to their god to reward the repentant in the afterlife, but its the Paladin's job to send them there...but that is only in the case of the god & Paladin's bitterest foes. You see this in several of the "holy warriors" in the OT.
The "New Testament" types, in contrast, hold Mercy as their greatest virtue. A foe who surrenders is to be guarded. A foe who repents may become an ally. Nobody is beyond redemption. The NT doesn't have much in the way of "holy warriors" but those paladins of the Chivalric era are often as much exemplars of this mindset as OT Biblical figures were of the former. (Caveat: in the case of supernatural evils- creatures who aren't just evil by choice, but rather by intrinsic nature- mercy may not be an available option.)
You get a DM who believes in NT Paladins only will thus have problems with a player playing an OT Paladin who is mowing down foes left and right.
Often heard key question of contention: "Why did you kill X?"
The flipside is equally true as well- a NT Paladin will often find his highly-held virtue of Mercy being taken advantage of if the DM structures the campaign world and its key forces to be more likely to renege on surrenders or being falsely repentant.
Often heard key question of contention: "Why didn't you kill X?"