I am not an expert gambler, just a casual one but from what I see here is that we have yet to find a true expert. So far I have only seen experts in Poker Tv series in real life.
Yes, poker players are considered experts and professional. If you have seen them in TV you have the impression that they are in control of the game. Unlike other games wherein we just base everything on luck so there will be no experts on that category unless the cards or slot machines are rigged to help you win big money.
Why just with poker gambling. I believe anyone can be an expert and professional with any type of gambling whereas he does not need to make profits all the times but just preventing losses is also more than enough to call themselves as an expert and professional.
Because, when making profits with a gambling is truly dependent on your luck factor then you cannot be having it as a measurement for your experience and being professional. Just managing things efficiently will be the more than enough factor to consider one gambler is an expert and professional.