Just discovered the demo mode under "extras" for DOOM on my iphone.

Why was this made? Who at id recorded themselves playing the game? They die within a minute every time.

In the original version of Doom demos looped automatically shortly after the title screen appeared. While you navigated the main menu, a demo would be playing in the background, sort of like an arcade game. It was never revealed who exactly made those demos, but it was likely John Romero or one of the other level designers. Also, they're intentionally not playing at their best. It's just meant to entice a player and provide background noise for navigating the main menu, just like an arcade game.

In the iPhone version of the game these demos can be accessed and played back from a menu. Since you can also record your own demos through some clever trickery, the intention is to provide players with an easy to way to manage and playback the demos they want, rather than operating from a command line or something like that.

It totally makes sense for Arcade purposes. I remember this being the http://www.youtube.com/watch?v=Ua1gdU-_VVg

Whoever did the iphone demo was pretty crazy, however. They didn't fire a bullet until they found the secret room with the shotgun and incurred a lot of damage up until that point. I don't even think they got through the yellow door.