I don't think saying "Bippity-boppity-boo" is a blessing at all. Do you?!?! Yet you use that as your example. Hmmm!!
I am told, Obi-Wan, that you are a priest. Unfortunately, we know all too well that such a vocation and position in life, in an of itself, does not protect one from error, and in this case, hyperbole. And some people (not just priests) get so caught up in emphasizing a rubric or rule when telling others how to practice their religion (such as thinking a minor word change makes a difference in the resulting blessing of the people), that they forget about relationship to God and to people in the practice of their faith.
Although I try to consider seriously what comes from the pulpit and from the church's hierarchy, I'm not someone who follows blindly (you would perhaps say 'obediently') everything that comes from the institutionalize church. Lord knows there are plenty of examples of error there. I do try to follow what I believe to be Jesus' teachings, and I have to believe you do, too. But my original statement still stands. Take a second look at your "up tight" perspective, Obi-Wan.
I suspect you have anthropocentric tendencies when it comes to the Holy Sacrifice of the Mass and the priesthood.
Firstly, as pointed out above, the priest works in the person of Christ when giving the blessing. The usage of “bless us” is at odds with this Catholic doctrine. With this false formula the priest becomes a mere presider instead of one acting in place of Christ. So not only is proper doctrine expressed in the correct formula but also all present realize the important significance of the priest. “May Almighty God Bless you” emphasizes his special priestly role, distinguishing himself from the laity.
Secondly, with the usage of the correct formulas and rubrics comes unity throughout the Church at large. Simply making up words for the Mass helps to eat away at one of the fours marks of the Church; her being “one.” Disunity is an offense to Christ and cause for chaos and abuse. Abuse is irreverence and spawns misconceptions, ignorance and error. So one Catholic church in one town can have vastly different liturgies and homilies than the one the next town over (both the words of the Mass and the external ritual communicate doctrine either explicitly or implicitly – reverent Masses demonstrate the Sacrifice of the Mass the Real Presence of Christ, abuses show a lack of understating what the Mass is and what the priesthood is).
Thirdly, properly following rubrics from both the perspective of the priest and people renders holy obedience towards the Church and towards God Himself. The tendency to shun rubrics and proper forms at Mass is rooted in erroneous perceptions on the primary function of the Mass and the strange modern obsession with participation (that is, false participation which reduces the Mass into a man-centered event, as opposed to authentic participation). In a man-centered Mass the rubrics matter little because the celebrant thinks creatively aids the people in some way instead of focusing on God and obeying proper authority.
Lastly and tied into number three, proper rubrics strike at the greatest capital sin; pride. Pride is present in all sin and caused the fall of man. We would benefit much with holy obedience and theocentric liturgies instead of the “creative” messes we see today.
Now, given the explanation here, it is apparent that we are not following “blindly.” Every rubric, rule, custom etc. has a purpose whether explicitly or implicitly that benefits the entire Church in obtaining the Catholicity she most desperately needs, holy obedience and of course humility, the remedy for all sin.