The attraction of the throttle tamer is that it makes the first few degrees of throttle actuation less sensitive.
In the days of carburetors, throttle smoothing wasn't an issue, the relative crudeness of the fueling system created a certain amount of lag between opening the throttle and the power increasing. This has all changed with fuel injection, which delivers metered amounts of fuel with incredible precision and speed.
The disadvantage of this can be that the transition from no power to quite a bit can be very sudden, a big problem in stop start conditions. The scrambler engine has characteristics which exacerbate the issue- a twin cylinder with a light flywheel, relatively high idle speed and plenty of low rpm torque. It's a recipe for a snatchy throttle.
The throttle tamer helps by spreading the first few degrees of throttle opening over a slightly wider arc. This makes riding the bike in traffic much more relaxing, especially so in wet conditions. Instead of having to meter the throttle by very fine degrees of opening, you have much more control over how much power gets to the back wheel.
Another way one might moderate this power would be to feather and slip the clutch. I believe that could be why Malcolms clutch had such a short life. Riding in London traffic would be an unpleasant experience with a throttle as sensitive at low rpm as the scramblers. Leading to excessive use of the slipping clutch to do the job of smoothing out the power delivery.
I worked as a dispatch rider in London in the early 80s and even with carburetor fueling, clutch life was an issue for the very same reason.
Riding largely on open roads would probably create the impression that there isn't much of a problem, a day riding in London traffic is very different.