History:
The first use of a belt buckle is found when belt gained its greatest prominence. The Roman Empire. (This is the first time this week I've thought of Rome, I promise.) To hold up their girdle, they wore leather belts. But while holding their sword scabbard and riding equipment, it quickly became a way for soldiers to show their rank. The more prestigious you were, the more precious the metal. Regions of the empire and specific units began using distinct shapes. 
This carried on for the next 2000 years with royals, merchants, and many other classes and occupations. We see it widely used in the US during the Civil War. 
It found its place in cowboy culture with the creation of belt loops on Levi's in the 1920s. Rodeos had already taken root and Hollywood promoted it heavily.
Culture:
With the growth of rodeos and the titles that came with riding and roping, the buckles became more valuable. From local rodeos to national championships, you only earned these buckles by winning and the reward was given because of the risk to step into that arena. Just as with the Roman Empire, "rankings" began to form with which buckle you wore. Your age, ethnicity, and event were irrelevant. Your buckle gave you a seat at the table, respect from those in and outside of the culture, but, more than anything, it gave you a right to speak. But just as in the military, the more precious the award the more weight your words held. 
How Does This Affect Us Today?
As most know, buckles are still given in rodeos. In all of this time, there is no debate that rodeo buckles are still rightfully earned by getting in the arena (No matter how blind/corrupt the judges may be.) Therefore, respect is still easily found between roughies and ropes alike. What you might not know is they also began handing out buckles in honky tonk competitions. The United Country Western Dance Council (UCWDC) even carried this tradition over into the ballroom in the 90s. No matter the local bar or national ballroom floor, the buckle is only earned if you win the competition. However, the question if buckles in bar competitions are rightfully given is up to question.
What message do our buckles give once outside the boundaries of country music, cowboy hats, and country dancing? More specifically, should a buckle be given if we’re not wearing a belt to put it on?
That's not for one man to decide, but every consumers of our culture to decide. All I ask if you stick around to continue gaining knowledge of our history and traditions so your focus is not just on having fun, but also on respecting those who came before us in the process. Don't hesitate to do research yourself, so we're not your only source of knowledge and wisdom.
God Bless.