He was the Master, just not for very long.

On-screen, that is, of course.
What he got up to prior to Chameleon Arching himself is anyone's guess.

For a few years he took on the persona of a Benedictine monk in 12th Century Shrewsbury

^That image haunts me too!
I didn't think it possible for Simm's Master to get any worse, but him in that dress plumbed new depths of obnoxiousness and absurdity.

^Nail on head! Andrew Scott's Moriarty and Simm's Master are virtually interchangeable. 2 annoying cretins!

I wonder if it's a Moffat thing? Perhaps he thinks, "I don't want to make people fear the bad guy; I want them to feel an uncontrollable urge to SLAP him!"

Simm' s performance was putrescent, pathetic, puerile; feeble, faulty and fetid; it was dire, disagreeable, dreadful; not to mention stupid, superficial and sordid.

But IN NO WAY was it as bad as Bonnie Langford's performances of yesteryear.

It's more dramatic for the Master to regenerate offscreen and surprise us with his new incarnation. That has been made clear from the Missy storyline.



Given Moffat didn't write the Simm master then I'd say no, it's not a Moffat thing.

^True. However, Moffat's Moriarty (first appearance 2009) is clearly derivative of Simm's Master (first appearance 2007).

Interestingly, when BBC producers created the Master in 1971, he was pitched as a "Moriarty" to the Doctor’s "Sherlock Holmes."
But while the characters are intentionally similar, it is to the detriment of both series's that they were moulded in the Scott/Simm school of acting!