I think that the biggest difference between preference of platform and attached is riding style. I would venture a guess that aggressive, fast riders prefer to attach their foot. More leisurely riders likely prefer platforms. This is in no way a blanket statement, just a hypothesis.

I think this is why many mountain bikers and racers prefer clipless. Except the downhill riders out here who all seem to use use pinned platforms. But I have seen my lab mates leg after a pedal strike and it is not pretty.

Some people adapt to new things better and are more adapt than others. Therefore clipless can be a challenge for some and second nature for others.

Ultimately it is personal preference and what one gets used to. I personally ride aggressive and fast compared to most commuters I see; I use clipless.