In actual practice the monk class was one of the weakest classes in 3e and the mystic theurge suffered from the obvious balancing act that was a spell caster without a full spell progression. That didn't stop the "chicken littles" of the interwebs from over reacting.
When I first got the 4e PHB I looked at the classes there and after reading them I surmised that the Warlord was an interesting class but really did not grab my attention. A couple of months later I had to "volunteer" for the D&D Championship Open to fill a seat. I had no skin in the game so I took the last pregenerated character left after everyone had picked, the Warlord. Let me tell you, the class played significantly differently than it had read, and was a total blast to play.
That is one of the reasons that I don't "judge" anything anymore unless I've at least played it once or twice.