As an overseas American who is painfully aware that she has zero effective representation in her home government (this is true even though she pays taxes and votes), I would say, "Au contraire, Monsieur."
It does matter. Even if the French abroad don't pay much attention to this fellow, the very fact that he exists is a strong sign from the French government that it takes its diaspora's concerns seriously and it wants to maintain contact with them. Perhaps the Secretary of State to the French Abroad does spend most of his time putting Frequent Flyer miles on his Air France card but that doesn't mean that he doesn't do any good. If nothing else, he's out there showing the French outside the Hexagon that they are still a part of France wherever they choose to live. And he's already shown that he's aware of issues of concern to ex-patriates. See this video for his program and his views on double- taxation for French citizens abroad.
In addition the French abroad actually have real representation in the French Senate. Article 24 of the 1958 Constitution specially establishes the right of the French living outside of France to have direct representatives in the French Senate. On the Senate website http://www.expatries.senat.fr/ I count no fewer than 12 Senators representing 1.5 million Frenchmen and women outside of France.
As an American abroad I can only look on this with envy. I can't even get a presidential candidate for 2012 to answer email (I tried the Republican side to no avail though I assure you that I am now being spammed continuously for campaign contributions. Maybe the Democrats would be more responsive.) 6.3 million Americans abroad (most recent count) and we might as well be invisible. It really is enough to make you want to weep in frustration.
It also makes you think very hard about your government's relationship to its citizens at home and abroad. If, having left the country, you are treated as though you are no longer part of the nation, it does makes you wonder why you are fighting so hard to maintain the ties. And then when you see a state that does cares enough about its citizens abroad to reach out to them, that makes it relatively easy for them to participate in the life of the nation, well, it does make you think that this state may just have something pretty special.