Weird naming is definitely part of the problem. I think the other part that makes git painful for beginners is that it does not mandate a workflow (do you have a central authoritative server? where is it? Do you merge master into working branches? Rebase all the time or never at all? Squash commits, or not? Etc). That means that as a newcomer you have to decide for yourself what workflow to use (at a point in time when you have no experience to help you in making that choice) and when you read tutorials or advice online you have to be able to spot whether the author of the advice is using the same workflow you are or whether their suggestions and command line options will not work in your situation. Earlier version control systems tended to be more dogmatic about how they were used, which is less flexible but easier to get to grips with.
I think the other part that makes git painful for beginners is that it does not mandate a workflow
That's a very good point. Every company I worked at that used SVN back in the day used it in basically the same way, making it very easy to get started. With git different projects even within the same company can have completely different workflows.
that's the only reason it gain adoption among other projects, which already had (different!) well-established workflows and let to it being where it is now.
