Beskar just like kortosis is not canon in any way. Only reason we have vibroblades is because lucas wanted a weapon
for grevious bodyguards that would work against lightsabers, and vibroswords were the only viable option that were used alot in the EU.
Actually GL said relatively recently that nothing except a lightsaber can block a lightsaber. But then again he is a complete nutjob and keeps chaning things that he himelf has said previously. A perfect example of this would be that the IG-100 MagnaGuards had lightsaber resistant vibrostaffs (designed and approved by lucas) and then a few years later he just blurts out that "nothing can stop a lightsaber except another lightsaber" thus contradicting himself.
But thats beside the point.
You said trooper armour was nothing but enviromental protection and that is wrong. Even within the extremely strict "movies only" canon that you seem to adhere to.
And the whole point of this discussion is that you lot (yes, im gonna go that low) seem to think that jedi only ever fight in plain brown robes. And you base this off the fact that they do so in the movies and thus it must alway have been so and will always be so throughout the history of the galaxy.
Going by that tho, one could also say that a whole slew of alien races cannot be jedi simply because there were none in the movies.
This insistance that jedi should never ever wear armour is very strange, especially since they have in very high-level canon material like the clone wars.
Also, take a look at what is considered "canon" when it comes to star wars: http://starwars.wikia.com/wiki/Canon
Beskar and cortosis is indeed canon... it is C-Canon.