It is hard enough to do what is right. Our wants, desirers, egos, social pressure, and the like often get in the way of acting properly. Even when we do the right thing, our motivation may not be the purest. We may act the way we do as a method of receiving the accolades of others; for honour, wealth, or acceptance in a social group.
While the Jerusalem Talmud rules that one makes a bracha upon construction of a sukkah (Sukkah 1:2), our practice is not to do so, seeing the making of the sukkah as only a hechsher mitzvah, a necessary (and laudatory) preparatory stage to the mitzvah itself, that of dwelling in a sukkah. When all is said and done, it matters little who makes the sukkah. The Gemara (Sukkah 9b) allows sukkot ganbach and ravkash, acronyms for sukkot made by those not obligated in the mitzvah, i.e.
Our tradition has long taught that it is a great mitzvah to do the right thing, even if for the wrong reason. “A person should, leolam, always be engaged in Torah and mitzvoth even if sheloh lishma, not for its own sake; as from doing them not for their sake, one will come to do them lishma, for their own sake” (Pesachim 50b).