dddd

I'm willing to bet that 90% of the naysayers to DT shifting have not ever ridden a DT-shifted bike having both a Shimano Uniglide freewheel (or cassette) and a "UG Narrow" (or succeeding HG50/70/90) chain. While there are other DT-shift options that work extremely well, there are/were many bikes from the old days which didn't have the right combination of pieces to make DT shifting such an effortless task as it can be.

Properly set up, a DT friction-shifted bike doesn't need fine-tuning to work well on the road, since the rider almost effortlessly selects gear position by feel and by sound.
This is helped by the tactile feedback of a quickly-engaging chain/sprocket combo which affords larger "windows" of lever movement (within which solid and quiet transmission occur), and by the very short length of control cable that suffers from almost no elastic "error" between shifter and derailer.

The riders who use DT shifters understand. Those who don't may only consider the added effort of having to drop to the saddle to make a shift or to have to delay a shift during hard braking, or over rough ground.

I'll concede that there are some bikes that seem to have too close of a proximity between their DT mounting bosses and any glove/finger-grabbing gap between the fork crown and the front tire, so if one notices any tendency toward having a finger sucked in during careless shifting they should address that issue immediately by adding some sort of shield or a fender. I once witnessed a rider go over the bars and left with a bent frame and fork from such an incident, and myself owned a steel Specialized Allez with such a tendency to grab a finger while shifting.