Your reason is one of them - they like to be in their exclusive club without any "upstarts" horning in. They also know that higher taxes really won't affect themselves at all. There is no way to really tax the wealthy if they don't want to be.
Rush said yesterday that it was to keep the peasants with pitchforks away from their doors. Here's an article that goes into the "fear of envy" that liberals have as well:
The Secret to the Suicidal Liberal Mind
I maintain that the House should craft a bill that specifically NAMES Gates, Buffett, and every other rich moron who CLAIMS to want their taxes raised (and there are signed petitions and websites all over the place where hundreds of names are available), and do exactly what it is they are asking for - - raise their tax rates.
Meanwhile, leave everybody else alone. (How rude and selfish is it for Gates and Buffett and the rest of that big mouth crowd to promote more government confiscation from OTHER people, people those punks don’t even know? /headshake)
Gates actually has another motivation to embrace liberal positions - to keep the government off his back. Once burned, twice shy.