Why do we not make a Bracha (e.g. every morning) on the mitzvah of honoring one's parents?
The Rashb"a writes in his Tshuvos Volume I: siman 18 that kibud av vaim is like tzdakkah and charity is dependent on the receiver because maybe he will refuse to accept, and he (the giver) won't be able to perform the mitzvah. When the action of the mitzvah is not completely dependent on the giver then there is no bracha (from Sefer Pisgamei Oraisa which talks about many mitzvos without brachas and the reasons why).
I think with most mitzvos between man and fellow man (bein adam lachaveiro) there's no bracha; I believe it has to do with "how do we know you're doing it for the sake of the mitzva?"
But with regards to the question of why no bracha over saying the Passover Hagadah, they point out that to say "okay G-d you commanded me to show gratitude so now I'm doing it" doesn't sound right. So imagine it:
"Chaim, can you please bring the groceries?"
"Um, wait a minute Mom. Thank you Hashem, you COMMANDED me to honor my parents ... Okay Mom yes I'll bring in the groceries."
The thought process should be a bit more natural!
Also, it's further complicated (as it is with many acts to fellow man) by the fact that a given action may or may not be kibud av v'em. You can feed your father the finest aged steak and degrade him ("just eat the food and be quiet, old man!"); or you could have him hard at work at the millstone and still be honoring him ("if not for the millwork they would have drafted you, I'm so sorry dad.")
The answer for this question is the same as for all the other questions of this type: because it is not "asher kidshanu" – there is nothing Jew-specific about it. Jews and non-Jews do it alike, and therefore it is not a distinctively Jewish mitzvah.
Also no beracha for Tzedakah and Geirushin for the same exact reasons. As quoted regarding Tzedakah:
Rabbi Elazar of Worms (c. 1176-1238), writes in his Sefer HaRokeach (ch. 366) that the Sages did not ordain a blessing before any mitzvah like tzedakah, which is based on logic and common sense and is therefore performed by non-Jews as well. The reason for this rule is because the entire purpose of our doing mitzvos is to sanctify ourselves and to help us lead more elevated and spiritual lives than those around us - as we say in the standard form of blessing before performing a mitzvah: Who has sanctified us with His commandments. However, when performing a mitzvah that is also performed by non-Jews, as in the case of tzedakah, our sanctification as Jews is not readily evident and thus no blessing is recited.