I don't think it is belittling - I would gladly do the same as well. In fact, during the period of time my girlfriend was going to school, I did all of the chores because her degree was very stressful (high cost, high rate of failure) -- despite working fulltime myself.

Respectfully (!), your conclusion relies on a fallacy (perhaps more than one type). This type of fallacy is called an "argument from silence", in which you make an assumption based on a lack of information provided:

http://en.wikipedia.org/wiki/Argument_from_silence

In other words, without knowing all the details of my life (or Einstein's) you can not really conclude our motives, outlook on sexism, etc.