Well, its like with sports...
These athletes (or gamers) are not paid for doing sports... they are paid for entertaining an audience. As such, they are professional entertainers, it just happens that their chosen way of entertaining people is competing in sports (or games).
Now, most people that can live of youtube are also pro entertainers... no matter if they make their money off video reviews of games, giving the girls ideas on how they can improve their make-up or creating stupid cartoons. They all aim to entertain and hook their audience (and then maybe also educate them a little bit if that is what their videos are about).
Considering what videos can support a pro youtuber, pro gaming sound sane and normal to even a longtime skeptic like me.
Now, is professional tennis a job? Mmmmhhh. Can you live of it? Yes you can. Did people get rich doing it? Most of the rich tennis players are rich because of their advertisment contracts.
I have troubles calling professional sports a profession. It is a form of entertainment, a vessel to earn some money and a lot of fame, and can be a stepping stone for a long career of modelling and advertising, doing NGO work, being a trainer or other official of sports associations.
But an athlete does not produce anything and does not provide a service (besides entertainment for the masses).
Granted, there are many "Jobs" that are actually called jobs today that share the same traits. Is acting a job? Is modelling a job?
To me, the constant fight of many E-Sports people and ESPECIALLY their fans to get e-sports recognized as a real sport / career / job just shows the insecurity of the people involved. E-sports do share many of the problems more traditional but underapreciated sports like women soccer have, and there should be a general push to make society as a whole take it more serious.
Still, trying so hard to convince people that their own view of things is wrong is just pushy. To me, american sports like Football, Basketball or Baseball are kinda cheesy, with hard to grasp rules, a complete overabundance of ads and a US-centricity that looks just amusing to an old worlder... that opinion will most probably not be swayed by fans trying to convince that I am wrong. It might be swayed if said sports change in a way that appeases my very european tastes better.
On the other hand, me not appreciating US sports (and most other sports too to be honest... so boring to watch a bunch of guys play with a ball on a field of grass) shouldn't stop any of the fans from having fun watching the games. Me blogging or posting about how stupid a sport is is just personal opinion and shouldn't affect peoples enjoyment of said sport.
Why the hell a) do e-sports fans care so much as how the world sees them and their sport, b) does i matter if pro gaming, or any sport played as a pro, can be considered a profession or not, c) if pro gamers get ridiculed and belitteled by many (all celebrities get that, stop whining), d) if your own hobby as a spectator to such events gets ridiculed?
Geek culture as a whole is still belitteled by a society that hasn't caught up to the fact that since 10-20 years, they are ruled over by the geeks. Geeks of many types and facettes have seeped into positions of power, and the geeks strong point of focus, technology and long term visions, have become one, if not the most important factor in todays economy.
What do you care about the opinion of the peasants when your own "caste" has moved to be the dominant on the planet?
E-sports will not go away, it will only become bigger over time. Instead of whining about the peasants perception of the spectacle, tune out their insignificant babbling and enjoy the spectacle yourself.