A Monk has Dimension Door, abet limited. A Monk also has Tumble and the highest base move in the game. So, yes, the caster with dimension door (often me) is left using standard actions to get around while the Monk has unlimited mobility. I'm a big fan of Dimension Door and Teleport and, honestly, I've never played a Monk but I have been in enough campaigns with Monks to believe that they have the best base mobility of any core class (but not a nomad psion with Inconstant Location up ). Why is it such a sour point to say that Monks are good at something? As was pointed out, they aren't good at the things that would make their mobility more useful in a broader sense.
Yes and every single caster in every single campaign will always have one of those three spells up, or any number of other spells, which completely negates the possibly of a Monk EVER grappling a caster. Come on, yes, it can be countered but so can a fighter smacking something with a sword.You can't grapple a caster because of Freedom of Movement. Or Fly. Or Invisibility.
I don't think that Monks are the best class and I think I'm being convinced that they are the weakest base class but they are not an utterly worthless character choice.