It's generally easier to spot right wing extremism because mainstream media and academia both lean (increasingly) left, and therefore you're less likely to see reporting on left-wing extremism for what it is.
It's a different way of being violent, at least here: the right tend to publicly assert the need for strong measures and bans and limitations and active (too active, mostly stupidly active) resolution of problems, while the left tends to force you legally by forbidding whatever is not what they want.
At the beginning of extremism, overt violence is defended by the right as "it was needed to make things right" and by the left as "I wouldn't be violent if you wouldn't be wrong". It's "I choose to be" vs "you make me be". The differences fade, but they are there.
In the far extreme, no differences exists anymore, both are in a "the enemy is trying to kill us, let's destroy them" mentality.
The media here is not particularly left-leaning: they are extremely divided, rather the most funded are the right-wing media. Strangely, the right-wing media are also more prone to absurd incoherence, so they are way easier to spot. Left-wing media are subtler (intellectuals are mostly left, after all, they know how to talk), so it takes a lot more attention and a lot more focus and logic to expose their incoherences, which also manifest rather late compared to the right-wing foaming madness.
I suppose this much is true: the left has a much more complex ideological building, so they are harder to nail to their logical shortcomings, while the right tend to be more direct and rambling, less structured and more gut-feeling. The left usually tries to spin thought around you until they convince you they are right, the right usually tends to stubbornly intimidate you until they convince you they are right.
Think of a straight line, with a right side (-), left side (+), and a center (0). Obviously, the further you go on either side, the more extreme it is. Well, if you place a dot somewhere on the left, your reference of extremism on that side is distorted, because you're already starting from somewhere along +, but not from 0, therefore the deviation from where you stand is diminished. Conversely, perception of extremism on the other side would be amplified.
Mostly, I think you are correct, here. The thing is, though: when I look at the US situation, I see a right-wing which is -on average- more on the right than here, and a left which is -on average- more rambling than here. The US seem to lack what here is the proper "left-wing": either they are some center-to-right or right-wingers, or they are left-nuts. In the US, I might even vote Republican (not easy, but possible), while I will surely never vote the right-wing here.
FYI the right also starts from a place of non-violence. Essentially, neither (moderate) wing espouses violence, but both extremes endorse it, as is expected from any form of extremism/tyranny. The right had Nazi Germany, the left had Communist USSR. Fascism exists on both extremes, it is not exclusive to one side or the other.
I agree. In the end, violence is violence. When at the extremes, actions are not dictated by logical thoughts, but by how the mind has been wired or rewired, so the differences fade out and eventually disappear.
You also stated the media tries to please the public and therefore more lenient on left wing nutjobs. Many on the right (I among them) would challenge that assertion, stating the media has been assisting in creating the narratives, rather than just reporting on them.
This really depends on the specific case you take as an example: I have seen both creating narratives and both passively multiplying the effects of something just to get more click/money/readers. The best media creators of narratives, here, have been on the right, not on the left. Disgustingly and continuously fallacious: a simple logic analysis showed you that they could not believe what they were saying. No sane, intelligent people could and those people surely had the intelligence to get those jobs, so either they are stupid, or they are lying. And I don't like to underestimate people as an answer to a doubt.
Left-leaning media tended more on the "everybody say it, so we say it too"; no logic, no critcal thinking, sloppy, empty, repetitive ideas. In some cases, they supported two things that seemed ok together but that are actually impossibly contrasting just a bit further down the line, so much that if they had thought that as a strategy, that would have been counterproductive.
Left-wingers media tend to believe in the stupid things they say, right-wingers media tend to say the stupid things they say even if they don't believe them.