[i_c_b]

"You can even tell that from the quality of Quake's levels which start with beautifully crafted and intricate levels, and as you approach the end, progress into "whatever, let's just ship it, this is gonna sell" kind of levels that were mostly just boring repetitive filler to pad the play time."

IIRC (this is well-documented if you want to double check), Tim Willits made most of the Episode 1 maps, John Romero made most of the episode 2 maps, American McGee made most of the Episode 3 maps, Sandy Peterson made most of the episode 4 maps, and John Romero made most of the level 1, military base themed maps in each episode.

The episode 4 maps are often barren, lacking in details, and missing much of the beautiful interconnections of earlier maps... but this is also true of Peterson's maps from Doom (he did a lot of episode 3 in the original Doom, IIRC). So I think it's more of "this guy might be a strong game designer in a lot of other contexts, but the specific needs of making cutting edge Doom/Quake style maps isn't a great fit for him".

I was at Raven Software at the transition from the Doom engine and other 2.5D engines to Quake (and then Quake 2, and then Quake 3, and then Doom 3), and there were a number of existing designers who were fine game designers in earlier, 2d contexts who found their skills severely out of sync with the changing demands of 3d map making, and most of them eventually had to transition to other roles or leave the industry.

[badsectoracula]

FWIW while i also found Petersen's maps on the weird side geometrically, at the same time i think they were among the most interesting to play (both in Doom and Quake) as he often tried to come up with various gameplay tricks and traps to break the "mold".

His Quake maps especially give me the impression that he was more into trying to come up with ideas on what is possible for the player to do in the freedom allowed in 3D space than how to make a good looking environment (especially in Quake's theme that didn't really have to conform to any realistic constrains and could have shapes floating in space, physically impossible architectures or whatever).

[i_c_b]

I think there's a couple of orthogonal issues here.

One of them is the nature of interactivity in the levels themselves. There's a spectrum between having a game grammar made of distinct discrete interactive reusable objects and then building unique situations by assembling them in interesting ways, versus having (essentially) unique scripted traps or interactive things or set pieces that only show up in one place. Older action games that inspired Doom tend to draw from that former tradition; a lot of FPS games that came after Quake tended to go more down that second road. Quake's trigger system specifically opened up the door to a rudimentary kind of visual scripting that made the latter style of design more possible in a way that wasn't possible in Doom (although it was possible in Hexen via HexenC(?)). I think you could say that that style of design really came more into its own with Half-Life, which foregrounded unique interactivity grounded in very specific, themed levels much more clearly. Doom at its best seems like it's much more in the design space of, say, Robotron and old Mario games. Fewer unique set pieces, much more focus on discrete interactive toys to be recombined... and given id's background with Commander Keen and their earlier recreation of the first level of Mario 3, this design influence shouldn't be a surprise. Anyway, Quake feels like it is at the intersection of these two styles of design.

I think it is true that Peterson did try to go more down that second road of design in the episode 4 maps in a way that there was less of in other maps, and that it interesting.

But the other thing that sticks out to me more so, in terms of level design, is about the way the space is shaped. A lot of the very best Doom and Quake levels have a tendency of having different parts of levels intersect and interact in interesting, playful ways. The order that you see areas is different from the order that you hear areas is different from the order that you can attack into or interact with areas is different from the order you can move through areas is different from the order that different kinds of enemies can move through areas or attack areas. And that changes as you progress through a level, get keys, and activate switches. There's a tendency for levels to start somewhat linear and movement constrained but give information about later areas in a somewhat more non-linear, tantalizing way, and then as a player progresses, for the player's movement in a level to become more like a multiply connected graph as switches, keys, and activated lifts make a lot of one-way paths become two-way. And that style of design plays to the strengths of Doom and Quake using BSPs for levels as their fundamental data structure - BSPs specifically make these kinds of weird and surprising visual and physical intersections between areas manageable in terms of computational performance on 90's era hardware.

Whether or not someone considers the design approaches I just outlined appealing is fundamentally an aesthetic issue, obviously - there's no one right way to enjoy a game. But my general sense is that the Sandy Peterson maps in Doom and Quake tend to explore these approaches to play much less than the maps made by other designers.