A lot of the people on 4chan will act like unapologetic assholes, but at least they’re not self-righteous about it. And, if shown legitimate proof of something, (based on what I’ve seen) they’ll usually accept it, whereas Tumblr prefers to pass around bogus statistics, and cling to emotional pleas, rather than logic.
4chan often behaves like idiots, but they’re aware that they’re behaving like idiots. That’s the whole point. People go there to be anonymous assholes on purpose. Meanwhile, Tumblr is filled with bullies and rejects that think they’re doing the world a goddamn favor by acting like snide, entitled little shit mongers.
4chan will call you a “faggot” regardless of gender identity, which appears to be generally understood to the point where no one even gives a shit anymore.
Tumblr becomes irrationally outraged when you somehow don’t already magically know the “preferred pronouns” of someone you hadn’t even heard of before, even when these “pronouns” are complete crocks of shit like “bunself”, or “princesself”. They then become indignant if you don’t fall to your knees and cater to every last one of their demented little demands, and treat them like the extra special little snowflake that they think they are.
4chan fields obvious inflammatory comments with relative ease, simply by dismissing them as stupid, humoring them for a laugh, or ignoring them from the start. When vitriol does happen, at least it’s mostly reserved to two morons having a witless tennis match of words while everyone else goads them on for the sake of entertainment.
Tumblr takes every goddamn thing as though it’s deadly fucking serious, to the point where people are afraid to voice their opinions on their favorite cookies, lest it somehow “offends” someone.
4chan will bust your nuts until you can prove a claim you’ve made.
Tumblr will gladly make viral the “news” that the sky has suddenly turned neon green, and is raining Nickelodeon Gak - if there’s enough of an emotional, impassioned plea to do so. Especially if they claim their “child” or “younger sibling” saw (and was upset by) this “incident”.
If you like something, and express it, 4chan will tell you it’s terrible just to piss you off.
Do this on Tumblr, and someone will claim you’re “oppressing them” simply because they don’t happen to like it. Then, through emotional manipulation, they try to spread the mindset that you’re somehow “scum” just for enjoying something that they don’t.
While I wouldn’t recommend it as a place to go to “have fun”, 4chan has actually become more welcoming than tumblr at this point.
And that’s just fucking sad.