Because most ultrabooks are designed similar to the MacBook Air, it could lead to serious legal issues with Apple's patent.
http://www.notebookcheck.net/Apple-s-Macbook-Air-patent-might-harm-Ultrabooks.77423.0.html
Why wudnt all Apple's competitors just stop producing, just dont fight Apple, make sleeves for iPods, headphones, anything. The dice is loaded against anyone who competes with the most venomous underdog ever that the media so likes to cuddle.
I wud suggest that in order to avoid design patent suits from Apple, vendors introduce a distinctive un-Apple feature, say a "bite" into one of the corners of their rectangle wares (rectangle you see, is now an IP of Apple and is prohibited to use by others) - this will make it distinctly different to Apple and make mockery of the bakrupt IP system. They shud call it "Apple-Bite" and upon power-up of their screens the first splash-screen shud say "This is not an Apple product"...
The irony will be evident, it will be cool to take the Mickey out of a predatory player who enjoys the smugness of the most egoistic and narcisistic brand - not for nothing all Apple products names start with "i"...
why isn't(wasn't) the sony x505 presented as prior art and be done with this nonsense...