Magplug; no it isn't. Just that a very few of the skippers like doing it. SOPs and ops manual state that the company prefer reverse thrust be stowed below 60 kts on the landing roll due FOD and pax comfort. Also most effective braking from reverse thrust occurs at the higher speeds ie; immediately after touchdown. Cos of the 25 min turnaround brake cooling is an issue, but on a cold wet windy day..?
Lots of urban myths out there, and there's bound to be one in favour of the bunch who do choose to use reverse thrust as a braking device during taxi. Hope that answers your question.