Does the well-off law professor have cause to complain?

This guy is the blogging topic of the weekend; his family earns $455,000 a year and yet he worries about his taxes going up and the resulting diminution of real income.  I think we cannot permanently extend the Bush tax cuts; nonetheless, being a contrarian, I would like to explore the question of when a wealthy person has cause to complain.  I read about this guy and his pitchfork and it genuinely scared me, especially his description of Ben Stein and his intermingling of the political and the aesthetic.
Let's say you live in a country which has some rich people, some people in the lower middle class, and some very very poor people.  Or let's say you are a non-nationalist cosmopolitan.  Or let's say they discovered the indigenous people in Alaska and New Mexico were worse off than we had thought. 
In such societies, do the "lower middle class but not very poor people" have cause to complain?  After all, some large group of others has it much, much tougher.  Doesn't everyone who might suffer a loss have a potential claim to complain?  At what percentile of wealth does your claim to complain go away or diminish?  Even if it's an exponential function, can't Henderson's complaint lie within the shaded area, small though that region may be?  Can't a rich person point out that he has a higher MU of money than a non-rich person might think?  Or must that necessarily offend others?  What kind of genuflections must he package along with that information, so as to avoid being considered offensive?
Do you have more of a right to complain about taxes if you were going to spend the money, bringing about the treasured "stimulus," noting that right now the wealthy are more inclined to spend?  Do spendthrift wealthy people have a stronger right to complain if the multiplier on their potential spending is 1.5 rather than 0.6?  Should wealthy people simply acquiesce to any policy change that leaves them in the top two percent, and keep their mouths shut in the meantime?
If you are wealthy, and complain about a pending loss, must you each time note that some people -- many people -- are worse off than you are?  If you read a bad complaint, and complain about it, must you note that other people are stuck reading far worse material?  Or is it OK just to complain?  What if some other country's rich people support political tyranny, or perhaps an oppressive caste system, or maybe they don't pay any taxes at all?  Can you still complain about your rich people?  Or must you put in a disclaimer that you don't really have it so bad, given that others, in other countries, are stuck with even worse rich people?
Beware of moral arguments which do not address "At which margin?"  I see a lot of attempts to lower the status of Todd Henderson, but not much real moral engagement.  
A lot of people just like to complain, and that includes complaining about the complaining of others.  
Oddly -- or perhaps not -- it's the people who feel they deserve their money who are the most likely to give it away.