Smartphone and tablets come with standard micro-USB ports and cables these days. These are universal standard accessories, meaning that they can be used on every other device. This just makes for convenience.
However, a few mad hatter brands fit their devices with custom ports. As such, those devices can be connected with only cables from the particular manufacturer or brand. It sucks.
You see, if you forget your cable at home, chances are that you are screwed for the day. If your cable gets damaged, again, you are screwed. If your cable gets stolen, again you are…yes; you get it.
In both above situations, unless there happens to be someone around you with that particular cable, you cannot charge your device, or use it as a mass storage device. It is frustration.
If you love your convenience and need to be able to pick any available USB cable for charging or for transferring files to/from your mobile device, stay away from custom connectivity ports.