That all sounds like project specific issues. A lot of FOSS projects are exceptionally well documented. The same with the attitude, some are wrose, some better. It doesn't seem like this is specific to FOSS licensing.

I (obviously) can't speak for everyone, but in my own case "toxic attitudes" tend to be a symptom of abuse at the hands of a variety of far more "actually toxic" people. People who wrongfully expect people like me to be their free whipping-boy and tech-support "guru" despite them being a total stranger who's never done anything to benefit me. Then when I refuse to help an abusive and entitled piece of shit, I'm labeled as "toxic" and "gate-keeping" and any number of other (often outright hateful) things that I've never been, but am learning to be because I'm sick to death of unjustified and unjustifiable abuse. Want "toxic"? Keep abusing people who are literally only trying to do and share a little good in the world (for themselves, and others). See how things go when there's nobody left on the planet who even wants to do good anymore, because it's literally more trouble than it's worth to do anything positive or beneficial in this life. People love to bandy that "toxic" label around when speaking of the Linux community, but almost nobody ever considers that toxicity (in the rare cases that it's even actually real, and not totally made up in some Win-Troll's head) might have some actual cause behind it, such as y'know… bein' sick and tired of abuse at the hands of actually and truly toxic people.