I flew out of FLL yesterday. At the security checkpoint leading to the US Airways gates, the screeners kept repeating their speech "we suggest that you remove all shoes, including sneakers and flip-flops." Everyone else in line took their shoes off. I left my moccasins on through the WTMD (no soles at all, just rubber nubs) and was not asked to remove them or otherwise harassed.

Since FLL is primarily a "leisure" destination, I'd imagine most of the passengers who go through security there are twice-a-year flyers, so TSA may just be trying to speed up the process for people who aren't familiar with the shoe policy. (i.e. that many shoes will alarm and that shoes with thick soles may be subject to secondary screening even if they don't have metal)