TDD is bad because it introduces distracting busywork. The actual typing isn't the actual problem.
In terms of just typing, I could probably produce something like 50,000 lines of code in a 40 hour work week in a moderately verbose programming language. In practice I'll probably crank out somewhere between 1000-5000.
It's the thinking that is slow. It's made even slower by adding additional tasks and context switching.
