The Star Wars Universe is vast and infinite, featuring an endless line of characters and groups, some original and interesting, others stereotypical and boring.
There is no question that those who use the Force are at the centerpiece of the Galaxy far far away, be they Jedi, Sith or something in between. They are the ones who make Empires and Republics rise and fall, singlehandedly destroy armies and battle stations and dabble in ancient and arcane powers that risk to tear the universe apart.
So why focus on a group that plays only a far second or even third fiddle in the battle between the Light and the Dark Side? The reasons why some prefer the Mandalorians above all other Star Wars organizations is a personal one: some admire their indomitable will, or their sense of honor and brotherhood. Others are drawn to their militaristic way of life and their skill with weapons which make them powerful enough to give even the mighty Jedi and Sith pause.
My reasons are more basic: the Mandalorians are, in my opinion, the only Real Thing in the whole of Star Wars. So few things make sense in George Lucas’s universe, be it giant slugs which supposedly are Master Criminals, weird powerful races which, nevertheless play hardly a role compared to mundane humans, technology capable to destroy planets and suns, but unable to detect a specific droid when it passes an imperial checkpoint.
But the Mandalorian clans are a showcase of a believable, enlightened and sustainable form of future society: a nomadic, self-reliant lifestyle is exactly appropriate for a huge universe, as is the formation of a tribe according to shared beliefs and goals instead of race or homeplanet. They have moved beyond kinship being a matter of blood relation only, and adopt and raise children, making them part of their family. In this they are much more advanced than the rest of the galaxy, with its Royal Families, political dynasties and families in which the Force is strong.
Constant competition and warfare keeps them alive and at the cutting edge. Personal responsibility and leadership allows them to excel; family and clan ties gives them the ability to pass on their experience and gains to the next generation, making them better all the time whilst maintaining respect for their timeless traditions and the deeds of their ancestors.
All in all, I belief that something like the Mandalorian clans could actually exit in the future, and survive and prosper through the centuries and millennia, whereas the Force and all it brings with it is rather run-of-the-mill fantasy magic.