This was a weirdly aggressive comment.
The solution is the pre-planning, which does not need a timer, nor is it a guaranteed result of a timer.
You cannot make players pre-plan. The timer encourages pre-planning, or at least rapid decision making on the fly. Both have the desired result of the game moving at a quicker pace.
It also has the benefit of creating an impartial tool for measuring, instead of relying on subjective “You’re taking a long time.” It is harder to argue with a clock. This is an advantage.
There was a problem, and in trying to fix it, the DM created a second problem.
What is the second problem?
I didn’t vote for him and neither did anyone I know :(