Any skill based game should have few professional players. However, I feel that a professional gambler is that person that can control his gambling activities by gambling responsible and limit his losses. On the other hand, if you feel that a professional is someone that wins more than losing in the long run, I don't think that we have someone like that. This is because, he will definitely be an addict which kills all the skills, fun and profits.
An addict may not possibly be losing the skills if they are also professionals in that field and happen to have more wins than losses. If they’ve lost those skills, then they won’t be called professionals because it’s the skill that makes them to be called one and not just by their addiction to it. However, some may still call themselves professionals because they’ve achieved more wins than losses in their games with no skills but just luck upon luck. So being a professional or addicted gambler, a skilled or luck based gambler all still falls back to how consistent you win and limit your number of losses in the overall game.
From my long term observations and experience in gambling, no one can win consistently in the long run. Which is the reason why I said that there's nothing like a professional gambler, if we want to judge a professional gambler based on his profits in the long run.
You seems not to get the message. If you gamble excessively because you feel you are very skilled in the game and making profits, when you become an addicted gambler, addiction will control your lifestyle and you will lose everything that you have won making your skill useless.