A fair point, but I would argue that it is not inherently the escort missions that are poor, but the way in which developers create them.
Before starting a flame war, let me explain... The reason escort missions are so difficult and annoying would most likely be the nature of AI in games several decades ago. With very limited AI development, games could not put in allied AI. This is why every shooter from the early 90's was a 'one man army' type scenario.
Because developers had trouble developing AI who could do more than simply shoot at you, they hesitated to provide characters in escort missions the ability to shoot back. There was also the belief that allies would make the games too easy. This was well before we advanced to the point careful balancing in today's games. There was also the side effect that with poor AI development, if you gave them a gun they probably end-up shooting you.
What I'm trying to say is that the whole concept isn't inherently flawed, games just need to be more creative about how they portray it. For example, relying more on the directive to the player than making the objective actually matter. Have enemies attack the player first rather than prioritizing the VIP. Or, at least don't make them so stupidly weak that one shot to the foot will kill them, and finally, give them a gun. It's really quite simple, it just hasn't been done.
Alternatively, just leave it to multiplayer, cos I don't hear anyone complaining about VIP in Halo.
