I can see that mentality in any house. Jerbiton (for the beauty of the experience), Tremere (pack mentality), flambeau (with sort of a noble beast spin on it), and Mercere jump out to me a great deal but I can easily see Bonisagus, Verditious and the rest too.
we just started a new saga and my Bonisagus is a Muto Corpus specialist. The turb is sailing around the Greek islands (in anticipation of the Thebes Tribunal release) and to prep I reread the Odyssey and the Argonautica. Tons of shape changing. I have him Mythic Blood: Descendant of Nereus and gave him a minor magical focus in self-transformation. I don't see a disconnect between his House and his passion for changing into different animals and elements.
Matt Ryan
I think the anti-shapeshifter hostility is too pronounced, essentially excluding any such from the house and the initial mystery is a bit weak, but downplaying the former to a dislike and adding a little to the later makes Bjornaer much less "narrowminded"(roughly) and more competitive.
I barely ever play Bjornaer myself but some certainly like it well enough ( although i´ve been a bit surprised how popular it seems among people on the forum ).
IMS bjornaers have not been around since 3rd edition. Nature oriented people tend to be exmiscellaneas. No love for the beastie boys around here, it seems.
Cheers,
Xavi
The Flambeau were never psychopathic and the Tremere are still sinister
The tremere are more about unity and standing together than political backstabbing. Still they are a force to be reckoned with and they make more sense now.
Flambeau were very psychopathic, kill them all and let god sort them out. They still have some elements of that but also more dimension in the new edition. I like the flambeau better in 5th.
I should know better than to start arguing about Flambeau with you Mark, but the opening sentence of Houses of Hermes, Flambeau Chapter reads: " Many Flambeau revel in the violent use of fire." And on the same page: "...Flambeau magi were chief perpetrators of wanton destruction".
But no, I'm just exaggerating. Even back in these days the Flambeau were military organizers and they had many members using subtle tactics and magic. It was just a common problem back them that some players interpreted them as combat-crazies, because they were easily portrayed as very archetypical in this way. And I know from many threads about this very subject that you had a more nuanced view of them in the pevious edition(s). But many peorple didn't, and because of this the new approach to Flambeau gives them more substance.
And the Tremere sinister? Come on! They just strive to rule the Order and Mythic Europe because they know what's best. Not because they want to but because they 'have* to... 
I currently play a Tremre and everyone always assumes I'm plotting against them. Like I'm some...Tytalus...Not to the effect that we as magi can't work together, they just point it out a lot. And I've never (ok, once) screwed anybody over. Our former Mercere was the most insistent advocate of this oppinion. But he was a dishonest swindler and thus I gave him his commuppance. Sinister - pfff - thats preposterous. 
Let's see, was it the 3rd or 4th edition grimoire that had the tribunal ruling about flambeau fighting on crusade as long as they don't use magic? Then there was the tribunal issue about the flambeau that got off on a mundane interference charge because he killed the entire village of witnesses. I think I remember two or three more tribunal issues in the 3rd and 4th edition that was based on flambeau burning or injuring someone and tribunal having to rule on it.
The flambeau were the one of the worst houses for instigating the Schism war. They are so peaceful that they are the one of the most common hopolite houses as key to join or die (they invented join or die. Bonisagus and Trinoma used persuasion and showing benefits).
Their house prestige is based on beating up other people. They are in many ways required to be bullies to thrive in the house. I have only once seen a flambeau played whose first response to dispute was not wizard war or kill them and loot the bodies. You have a problem, kill it.
The fifth edition is a lot richer with the cult of mercury, the more varied fighting styles, the milites that is more knight and honor driven instead of psychopathic.
Yes they were(or rather, enough of them were blatantly gungho, agressive and singleminded that the house in general almost deserved the reputation, and almost goes a long way when it comes to reputation...) and yes they most certainly are.