Could Doom have been more challenging ?

Could Blizzard have done better ? Could Blizzard have made their games less
complicated on purpose ? And what about idsoftware with Doom ? Does each
developer do this with their games ?
I thought I had seen it all but now : awesome, unbelievable, remarkable ... .
A friend recently gave me a compilation of the Starcraft/Broodwar missions
he'd made himself. He had put these together with the very best missions
he'd found on internet but then most severely altered to change difficulty
or to make them more fun. Especially the very last level (GeertFinal) is
extremely special : you see two other Terran tribes battle each other all
the time while you fight the Zerg. But if you come near the Terrans, both
attack you (!). Surprises are never far away in this level, and when you
think it's over... . Blizzard never made that ! Can it be that Blizzard
avoided to make it so complicated ? Or didn't take the risk to make something
so complicated ? And what about idsoftware, could it be that idsoftware did
the same with Doom ?
Also, in some levels, another race battles together with your tribes, but
indepedently and without your need to interfere. This race even comes to help
you when you're attacked. This allie has its own AI but is attacked too by
your enemie. So, sometimes you need to defend this allie or he could be lost
for the rest of the mission ! I wonder why Blizzard never accomplished that !
The fact is that everybody can make impossibly hard missions with their
campaign editor. But good balance between still possible but rather
challenging, that's what we need. I think, this "ExtraMissions"-zip from
my friend contains the best Starcraft/Broodwar maps ever made for
singleplayer. BTW I have done nothing here. It's all a friend's work, but
I asked him to share this with the "world" because they're really worth
being played and so I've put them on my server. Anyone who doesn't believe me
and who still has Starcraft/Broodwar lying around, just point your browsers to http://lena.servegame.com:1025
and download the ExtraMissions zipfile (14.3 MB in one file). The missions are
made especially for veteran players. Some levels are extremely difficult but all
can be played to victory, and in fact not all are difficult of course. Indeed,
the first level (Geert01) is rather easy. No need to say that brute force isn't
always the good path, ruse and good thinking can sometimes bring you far too
Also, take a look at the code of "GeertFinal" after you've played it. Isn't that
a beauty ?!? Also worth mentioning are "Badlandswar" and "DesertKerrigan". And
now that I've said all this, I come back to my starting questions : after years
of working on the serie, the Blizzard crew must have noticed the above mentioned
possibilities. So why didn't they make us a mission like GeertFinal ? Do all
gamedevelopers do this ? What about Doom ?
Enjoy gaming ... En taro Adun ...
Oh, BTW, if my server is offline, you can also get the ExtraMissions from
http://www.starcraft.org/scums/maps.asp?mode=search
Just do a search for the map name "extramissions" on this page. It's 15 zipfiles
all together here (ExtraMissions01-->15). It seems that I messed up during
uploading, so there is a 2nd number 02 instead of number 03. Just download both
02's. All zipfiles have a readme.txt to get you started and all files are about
1MB each. I'm in Europe, my server is daily at least online 10 --> 24 (Western
European time).
Lena