If each city is specialized in a product, or if each citizen that belongs to a city belongs to a certain trade, it will make our economy organized and for the first time efficient. However, is it more productive, probably not? But if it happens there will be some positives.
I think that trying to play to the strengths and special needs of some cities can be a good and positive thing. I also think some cities will benefit by trying to deal with some issues that are particular to their citizen's preferences. That is why I do support the idea of specialized cities.
Yes, I think that the concept of a specialized cities is a good one and will lead to cities being more safe for citizens and more productive for citizens as well. I think that specialized cities now have a time and place in our society, and can only benefit society overall as a whole.
Specialized cities will not work because if the industry goes through a rough cycle then the city will not be able to withstand the tough times. The best, most productive cities are diverse and can handle all kind of difficult situations. People are tempted to try this concept but it won't work.
Every city has their own unique culture and products. It is bad for a city to specialize in one certain commodity or good. It can be great during times of booms but when that market collapses the cities can crumble for long periods of times. It's better to have a diverse city.