There's a big difference between just making maps and using entirely different game engine. Like you could make map replacements for Super Mario Bros (NES) as a ROM hack, or just use the built-in editor of some games like Boulder Dash (on various 8-bit computers), and you'd have new levels but it would still run in the same exact engine. The key here is you're still using the same old technology of the time, because that's really the main limitation of a game. You can only go so far with it before hitting a brick wall, and have to use a new engine, or enhance the old one somehow (src code if it's available, otherwise disassembly or other reverse-engineering to find ways you can hack the engine, sorta like Doom+).
You're not playing a new game when you load up a random PWAD from your shovelware CD. It plays and looks more or less like the original (often worse in case of 1994 maps, but much better after people got more experienced). But when you start making big engine changes, like ZDoom and various other ports, then it doesn't play the same, look the same, or feel the same, even without loading those enhanced game mods. It doesn't play the same because it the engines (except Chocolate Doom, and to a much lesser extent PrBoom) don't try to emulate the original engine's behavior very closely. They also provide added functionality like mouselook, manual aiming, jumping, etc. It's true those can be disabled, but the engine doesn't enforce that while playing vanilla maps, and I'm sure many people use those features. It doesn't look the same because of OpenGL, higher res, and widescreen resolutions, etc. The various high-res texture packs, sfx packs, and such things have also been very popular items on this and other forums, so I'm sure they're used by many players. In fact, I seldom see a Doomsday thread that doesn't mention them. So yeah, you can' t fool me into believing everyone is just playing ZDoom or whatever like it's plain old vanilla. I know they want the pretty eyes candy and all that. ;-)
I really doubt many people here use doom.exe or Chocolate Doom as their default engine for vanilla maps, and even less use it as their sole or "go to" engine for everything. I certainly do, but probably very few others. I find it convenient though, but in a backwards way than you do: if a map doesn't run in vanilla engine, I usually don't play it. :-)
I understand why people want the advanced engines, and why they're here and how they came about. But they're not DOOM to me, they are evolutions of DOOM, each with various capabilities and goals. But the last, final IWAD releases of DOOM and DOOM II were v1.9 for DOS, and I think that's the real measuring stick for what DOOM really is. I mean, ZDoom for example as taken many Hexen features and integrated them, along with lots other stuff. Is Hexen the same as DOOM? It has similarities and shares some code, but to me they're not at all the same. In fact, I don't much play Heretic or Hexen precisely because I enjoy the lean & mean (some would say limited) gameplay of DOOM.
Edit: @GZ - You give the DOOM src release far too much credit. Fact is: other games that didn't have src were re-implemented by careful reverse engineering or just observing gameplay and trying to replicate it in a new engine. One good example is the old 80's RPG "Dungeon Master". There is a community for that game too, and many engines, some very faitthful to the original and others with many enhancements. But they were all created from scratch by that community. And in fact, before doomsrc there was a project "Dumb" that could play DOOM/DOOM2/Heretic, although not using the same rendering techniques as the real engine. But with a community this large, I have no doubt that a very close approximation of doom.exe could have been realized even without id's help.
Last edited by hex11 on 02-03-13 at 15:59