Even to the extent that is true, which I could quibble with, the sarcasm can be at the sarcastic one's expense, as a form of self-deprecation, or it could be at the expense of a person not present and one who may not even properly-speaking exist.

Sarcasm at a coworker's expense isn't wrong because it's sarcasm, it would be wrong because any social interaction at a coworker's expense is generally wrong.

Other than that bit, what you've written doesn't conflict with what I wrote. Even if sarcasm is used at the expense of nonexistent parties, it stands a reasonable chance of making those who don't know you well wary.

One illustration from my own life: I was very sarcastic as a younger person, but generally had no malicious intent. Once I thought I was getting along quite well with a girl, who was laughing at some of my sarcastic remarks. At the end of the evening, she stormed out of the room, upset after I made yet another sarcastic comment. This came to the great surprise of me and others in the group who knew me better. Here there was no evil intended on either side, yet sarcasm combined with the intrinsic difficulty in understanding another person created a very uncomfortable and socially destructive situation.