I don't think you're really understanding what an anarchosyndicalist is. Basically it means non-hierarchical trade unions and nothing else (syndicate is just the French word for trade union). It's pretty much the exact opposite of individualist anarchism. The kinds of things that anarcho-syndicalists recommend doing are things like starting cooperatives / worker-owner corporations, and studying various types of voting systems. So, the basic difference is that individualist anarchists want to
blow up the factory to score points against capitalism (or generally throw spanners in the works via hacking), whereas anarcho-syndicalists want to
build their own factory then implement democratic voting instead of management.
It was the most effective of any anarcho- or liberatarian- type movement at actually
getting things done (e.g. anarcho syndicalists ran the munitions factories for Republican Spain during the Spanish Civil War). They were in fact pretty effective at running things (because hey, funnily enough giving people a vote on important matters rather than barking orders at them seems to
work), but that came to a quick end because Franco killed them with his borrowed Panzers, while the Soviets didn't want the competition either, so they undermined them too.
Because it was successful is why a bunch of kids who don't know anything about it started calling themselves "anarcho-syndicalists" in the first place. It's the curse of
anything popular basically. Thing is good => thing becomes popular => dumb kids start talking about thing => thing gets labeled as "bad" because dumb kids like it.
And as for the legitimacy of current anarcho-syndicalists:
https://web.facebook.com/270528233152758/photos/gm.145537736068561/711285045743739/?type=3A presentation by Vicente Ruiz (hijo), the son of Vicente Ruiz, commander of a CNT Militia during the Spanish Revolution. The presentation will tell the story of the CNT exiles in Australia. Starting with their escape from Spain to Morocco, their foundation of Movimento Libertario en Africa del Norte in Beni-Saf, their imprisonment by Vichy colonial authorities and their subsequent settlement in Australia as UNHCR registered refugees. It will follow the foundation of Grupo Cultural de Estudios Sociales de Melbourne by CNT exiles in 1965 and their involvement in the establishment of the Tenants Union of Victoria and the Fitzroy Legal Service as well as the founding of Cruz Negra Anarquista (Anarchist Black Cross) in Australia.
... That's some serious street cred right there, and it shows how anarcho-syndicalist groups around the world aren't just created and run by
trendy kids, we're talking people who are the descendents of war heroes and the like who have been continuously fighting for worker's rights for a century. So no, it's a dick move to smear the names of these people, you're basically laughing at the descendants of people who got mass-murdered for standing up to Franco's fascist dictatorship, while the rest of the world turned their back on what was happening.
I mean, context matters. If a bunch of college kids make the "Anarchist Black Cross" organization, feel free to
laugh your heart out. However, when exiled war veterans who fought in the trenches against
Franco make "Cruz Negra Anarquista" ("Anarchist Black Cross") you don't get the right to laugh at them: those guys seen some shit. The "Black Cross" they're talking about isn't some abstract "edgy" symbol, it's the flag they literally fought under in armed combat.