I dunno man, I've watched the odd walkthrough when, for example, the sunday morning gloom becomes too much to bear, and the stark silence (broken only by the sound effects of doors sliding open, guns cocking, and obviously by the large bursts of action), was somewhat joyously unnerving. But I take your point, they are quite fast paced. I'm probably just a wimp.
No lie, most video games weirded me the hell out when I was a kid. I guess that was down to a low threshold for uncanny valley jitters or something. I played a few games here and there, don't get me wrong, but it wasn't that hard to grow tired of them. I've never bothered to even catch a glimpse of anything related to Doom 3, though I've heard it was really bad.