All this because osx doesn't do a thing that apple never claimed osx did.
http://en.wikipedia.org/wiki/Usage_share_of_operating_system...
I fail to see where your frustration is coming from, or why it's targeted at Apple. It's most likely just a calculated cost savings measure.
I'm not sure where you think said frustration should be directed.
Mini DisplayPort Connector
The Mini DisplayPort Connector is a small form factor connector designed to fully support the VESA DisplayPort protocol. It is particularly useful on systems where space is at a premium, such as portable computers or to support multiple connectors on reduced height add-in cards.
https://developer.apple.com/softwarelicensing/agreements/min...
2) Apple doesn't prevent you using dual monitors via other means e.g. USB / HDMI.
3) Microsoft/IBM had ridiculously high market shares (>90%). OSX is around 10%.
Apple writes their own device drivers and they write them to the extend their software and hardware needs it and no step further.