You're right that the lawsuit itself was not Jobs's personal doing, but the acrimonious personal dispute between Jobs and Gates certainly was about 'look and feel' and the perception that Gates knocked off Jobs's innovation. Gates was brought in by Jobs and shown his project in order to get Microsoft on board for Mac software. Then Gates came out with what Jobs thought was an imitation of the Mac UI, an imitation he believed that Gates could only have done by copying what Jobs had shown him.
Jobs's perceptions in that case or in the current case with Schmidt may not be accurate or just, but that doesn't mean they don't play an important psychological role in Apple's current strategy toward HTC, Google, and Microsoft.