Mark has a point, but I don't think it is the one he is actually making.
First, I think Patter is an awful word. On one of those 1950's game shows where you had to guess the words from clues, patter came up. The clues were akin to "meaningless, drivel, chatter" etc.
I think a magician's words can be a powerful tool both methodologically as well as dramatically and to stick one's hand blindly into a tool chest hoping to come up with the right one for the job is a position I cannot advocate.
I would be willing to bet Mark has a script, though it probably evolved out of performance as opposed to having been written from theory and memorized by rote. I also think a lot of people assume, incorrectly, that a "script" must be set in stone. It does not. I prefer to think of it as a spine. The script gives a performance structure and form. One can deviate when experience dictates it is wise, but that core structure keeps the show/trick headed in the correct direction.
I can imagine someone who has been "in the trenches" for years feeling as if their work is more free form that it is. It's like a great jazz man telling you "just play what you hear." But I think this comes from being such a master of your instrument that you are making conscious choices so quickly, that you know your chord changes (script) so well, that it seems like you are completely extemporaneous when in reality, there is a lot of ingrained structure swimming beneath those waters (to mix a metaphor).
HOWEVER, I can think of dozens and dozens of times when I have seen a magician "ACTORRRRRR! (to be read ala Lovitz) perform. They are forced and stentorian. They speak at the audience, not with them. They over gesticulate. And they usually mysteriously acquire some sort of faux British twang.
Of course these people understand "acting" as well as a lot of "magicians" understand "magic."
Like magic, I think a lot of people take acting classes and assume they are now actors. They think acting is little more than "being louder." And I agree with Mark, in those cases, there may be no worse combination.
In the best of cases, acting becomes invisible. It should seem real. Seems an appropriate match for magic. However, to achieve that "reality" in either art takes much more work than many might realize.