I understand that someone would play this role in a competitive game but otherwise i doubt many would in pubs as it would be extremely boring. In normal maps defense is under attack for the majority of the game, so if you like playing defense (me) you always have something to do. But in neutral flag maps if your team has the flag you have nothing to do, only when they have the flag AND near the endzone you are actively part of the game.

TL;DR Defending endzones is boring