[bryanlarsen]

Eventual Windows competitors will have more than one port, but they won't be identical. Only a single port will be able to be used for charging, the others will be data-only.

That's too inelegant a solution for Apple, they'd rather just have a single port than have two ports that look like they should be identical but aren't.

[aeturnum]

Then just have two ports that are identical? Is there something that holds them back from charging from two different locations?

[bryanlarsen]

A port that supports 100W power input requires a significant amount of external components. Switching that between locations is also a significant challenge (IOW, it costs significant money and space). Just switching between the wall and the battery is hard enough, adding a third location will add a significant amount of space and $.

It will also add significant protection costs: what if somebody plugs 2 chargers into the laptop? They'll be at almost but not the same voltage, and amperage levels will be high enough that significant damage could result. Obviously the laptop will only do the upgrade voltage & amperage handshake with one of the chargers, but I imagine that redundant hardware protection will also be required.

[WorldWideWayne]

My Dell Venue 8 Pro comes with a single micro USB port that is used for both charging and data.

I don't really consider it to be a competitor though because Apple doesn't offer anything that can compete with a touchscreen device that can be used as a tablet and also a full general purpose computer.