According to news reports, it looks like he wasn't mugged at random, but in the vicinity of his own $200k McLaren...of course, this should be NO excuse for these criminals, nor for those of us without a McLaren to feel entirely safe ;-)
As you say, larger cities seem to be more and more the playground of these lowlifes, especially here in Europe. I spend my summers in Italy, and this year I can literally hear of these reports on a daily basis...Milan, one of my favorite cities, is probably no safer than London or Barcelona (or Detroit or Lagos) anymore ;-)
Personally, I still enjoy my watches A LOT (I'll never let these criminals kill my hobby), but I do take a few more precautions than in the past, including choosing the watches I wear with more attention. Even though my neighborhood is (reasonably) safe, I keep very little at home and all the rest in (several) banks. As a self-gift this summer, I just bought a new watch AND another safe in a bank ;-) Cheers.