No-one really cares about Mandos except fanboys, which is the only reason Mandalorian characters are forced into the narrative as is (see Boring Cadera and Akaavi Spar).
I get the distinct feeling BioWare understands just how awful and ****** Traviss' writing is and are treading the line between openly mocking Mandalorian fanboys and giving them a little bit of the awful trash that they like (Best Bounty Hunter option in the game is telling the Mandalore to go **** himself and watch him get all nerd-rage on you while the rest of the Big Five mock him behind his back).
Hmm. So if Traviss' books are so awful, why are you
in the minority about this, whereas I can link you to a whole website of fans of the novels? All she did was base the Mandalorian culture on the ancient Spartans, so what? Are the Spartans Mary Sues? Hmm?
I understand some people take Mandalorian fanboying to the extreme. Not me - Jedi are awesome, Sith are great, and so are Mandalorians. It's just another culture in Star Wars - why do people get so upset when there's a non-Jedi, non-Sith culture that gets focused on? Is it the Jedi killing? It's been said once, it'll be said again - the Force makes the Jedi powerful, not kriffing gods. If the Jedi were as powerful as you suggest, then Grand Master Zym would not have been killed by Braden (a non-Mandalorian, BTW!), Jace Malcom couldn't have beat the stuffing out of Malgus, and despite all that, the Mandalorians are never
portrayed as invincible/immortal. Revan killed the shabla leader
of the Mandalorians, Jango Fett's entire army got slaughtered by Jedi (so much for Jedi killing, huh
?), and Ulic Qel-Droma curb-stomped Mandalore. Great fighters =/= Mary Sues.
And to the beskar'gam. Traviss was not
the one who invented it - that was as far back as Tales of the Jedi, when the Mandalorians were a race of Crusaders working for Ulic Qel-Droma. Not exactly demi-gods or Mary Sues, are they? So one
culture has stronger armor than others. The Voss have above-average rates of Force sensitivity among their people, all
the Korunnai are Force users, and the Echani proved to be possibly the best martial artists in the galaxy. The Mandos are only nomad warriors with one
advantage of an ore that can be mined on their planet. Besides, usually 1 Mandalorian does not match 1 Jedi. It takes 3 or 4 Mandalorians to beat a Jedi.
There, I just threw all your reasons for them being Mary Sues out the window. Care to counter?