If mini versions of bus connections work the same, why not use it for everything?

You know how most busses have mini versions of their connections. USB has mini-USB, DisplayPort has Mini DisplayPort, HDMI has Mini HDMI...
But all these mini connections work the same as the original. So why are we using these regular-to-mini cables and adapters to connect small devices to large devices, when we can just have all devices use the mini versions? You can fit a small port on a big machine, but you cannot fit a big port on a small machine. And with MacBooks getting thinner and thinner, the regular USB is becoming too big already! Apple and Intel is developing a USB type C, but why? What's with all these variations; mini-USB, micro-USB, USB type B, blablabla? Why don't we just use one variation for everything? This would eliminate the pain and hassle of using different cables and adapters.


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I have been reading this article. USB A and B are to prevent power sources from being connected to other sources, and to keep them only be connected to power receivers. But USB type A and B also have their mini versions anyway! Why not use Mini-USB A and Mini-USB B?

Also, this idea does not exist with HDMI and DP; there is no type A and B; anything connects to anything.