Willing to die for the cause will sanctify His name. People will take note of your dedication. If they think lowly of a certain Mitzvah, then you do not have this benefit. In fact, there is no point of splashing currently unpopular ideas in their face. They will say the opposite of ברוך… This is why, throughout the generations, we’ve had many apologists giving contemporary reasons (or excuses) for Mitzvos.
This whole idea — that simply doing any Mitzva openly, even when it’s despised, is a Kiddush Hashem — seems to be a reaction to the opposite idea, that we should be ashamed of Mitzvos deemed inappropriate by the outsiders. However, you shouldn’t allow yourself to redefine your own ideas in order to win over someone else.
עם חכם ונבון is not about Muktzah (as of now), it’s about things that impress others, Chazal explain.
Returning money, is not a Mitzvah (and can even be an Aveira), and yet it is the prime example of Kiddush Hashem.