The way you've worded this makes it sound as though programmers of the era were somehow unaware of perspective mapping, which I can assure you is not the case at all. Affine texturing was a tradeoff of performance, nothing more.
Wolfenstein's correct texture mapping is due to it using raycasting in a 2D plane and rendering scaled vertical strips of texture, which just happens to be perspective correct because you only ever have surfaces at 90deg angles in the vertical.
As to why those extra triangles weren't used for detailing, it's likely because that would take up extra level data. Tessellation of an existing triangle into smaller triangles doesn't.
Wolfenstein and Doom are 100% correct because Carmack 'cheated' by deciding to never look down/up or draw slopes :-) so whole game is drawn with 'lines of constant Z'. Or as they put it
Chris Hecker (Microsoft/Maxis/etc): that's a classic Carmack thing which is like Fuck those general problems, Im gonna solve this other problem perfectly
John Miles (ORIGIN/Miles Design/etc): Its all about not doing the math, we were still at a point in time when you won by not doing the math
Wolfenstein's correct texture mapping is due to it using raycasting in a 2D plane and rendering scaled vertical strips of texture, which just happens to be perspective correct because you only ever have surfaces at 90deg angles in the vertical.
As to why those extra triangles weren't used for detailing, it's likely because that would take up extra level data. Tessellation of an existing triangle into smaller triangles doesn't.