Morkus from Orkus
That sounds like a pretty big exaggeration, unless you were just handing them powerful magic items left and right. I have played a lot of 3.5, and never did I need to pick monsters of +5 or +6 CR's higher. +2 or +3 points maybe, but never much more than that.
You may have been doing something wrong if that be the case.
Not an exaggeration at all. I didn't say that every monster in that range was viable, but that there were monsters that existed in that range that were. CR should be more accurate than that.