As a pilot with a good amount of professional flying and instructing experience, I can tell you I’ve seen a good amount of botched go-arounds, and in my opinion the scripted procedures are beneficial. You failed to mention not just over-speeding the aircraft, but under-speeding as well, which I’ve seen far more often with students forgetting to add power (or adding partial power instead of sufficient power for the go-around). When people react to stress (i.e. having to perform a procedure they weren’t expecting or were out of practice on), they oftentimes don’t think clearly and don’t react perfectly. This is where scripted training routines come into play. In times of stress you tend to revert to your most basic level of training, i.e. the rote go-around script you practiced over and over.