Right. Some people might say it's a distinction without a difference, because they might see, for example, that anyone who engages in trolling behavior is by that very definition, a troll.
But the I believe there may be some contexts where it's valuable to preserve the distinction. There are some times people engage in trolling behavior for good, or for a higher purpose. And while that might make them (technically) filling the role of "a troll" in that moment, that wouldn't imply that their main reason for being on the site is to troll.