Um...if you actually read the DMG you'd realize that adding 2 to the CR is supposed to be double the difficulty. (i.e. 1 CR 10 creature makes EL 10, but 2 CR 10 creatures make EL 12 - see Table 3-1 pg. 49 DMG 3.5) Besides which, the traps aren't impossible - it says in the into that a Rogue is a very good thing to have around for the dungeon...if you want to compare a Rogue with maximum ranks in Search and Disable Device of an appropriate level for the area and you'll see they are beatable if not easy.
This is not to say that the dungeon isn't unbalanced or poorly researched but your critic of it isn't even marginally well thought out. Maybe you should try reading the rules before lambasting someone else for their application of them.