There's little doubt that the transition to USB Type C connectors is in full swing in 2016. Laptops and smartphones alike are picking up the standard for its large set of features and promised ubiquity as we head into the future, and it's easy to understand the reasoning.
But, like so many new standards, at the moment USB-C still has a few drawbacks worth noting, and smartphones are probably the market where they're most apparent. First, there are practical concerns: how many USB-C cables do you currently have? If you don't have a USB-C smartphone or laptop, my guess is "zero." If you do, you still probably have far fewer USB-C cables than you do Type A to microUSB ones, and the same for wall chargers. This means carrying the right cable to charge your smartphone in any place you might need to do that - in the car, the bedroom, work, on the go, and anywhere else you might need to juice up. That takes a bit of planning. Type C cables aren't especially cheap at the moment, either, and while costs of production will almost certainly drop a lot in the next year or two (and price competition will rise), early adopters are quite literally paying the price for getting on board with the new standard in its infancy. Oh, and all those Qualcomm, Samsung, and Motorola quick/adaptive/turbo chargers you have? They generally don't provide fast charge speeds on USB-C ports, because manufacturers are opting to use the new USB power delivery spec instead. So, if you want the full 15W+ charge speeds everywhere, you'll need the proper charging brick everywhere.
More technical considerations are less obvious. USB 3.x Type C connectors are basically a non-thing on smartphones right now, which means that most of USB-C's big promises on connectivity and robust feature set go out the window. Current smartphones with type C connectors by and large use a USB 2.0 controller, meaning only USB 2.0 features are supported. USB 3.x features that rely on the Type C standard include things like display-out functionality, power and connectivity daisy-chaining, ethernet support, and much faster data transfer speeds won't appear on smartphones until USB3 does.
With all this in mind, it's not hard to see why some people could be happy to wait out the somewhat painful USB-C transition with microUSB instead. After all, who wants to buy new cables and chargers (not me, certainly)?
But then again, a reversible power connector is basically a godsend when you're trying to plug your phone into the charger in the middle of the night. And that's not nothing. So, would you prefer your next smartphone have a USB-C connector, or would you like to hold onto the old microUSB a while longer?