Therefore there are two choices:
Either they get regulated as other slot machine makers around the world, including being taxed as both a slot machine maker and as a slot machine operator.
Or alternatively just make a video game and sell that and not have to deal with all the regulation.
Of course if they are creating slot machines they should follow the related regulations. However there is nothing that forces them to make actual games. If they can make business by selling virtual slot machines let them do so as long as it's legal. After all they are not the only game publisher out there and if there is an actual need for quality games it will be fulfilled by other publishers.
Look at the threads about daily fantasy sports in HN. Many impassioned comments about how the ability to bet on sports is freedom, etc..
Card games are gambling. True, you can get gambling credits by grinding a lot in Hearthstone, but I feel this is despicable especially for a card game catering to mostly underage or very young people.
This applies to non-virtual card games too (e.g. Magic, Pokemon, Yugiho). Pack-opening is kid's gambling. They are made to encourage people to open more packs/make a deck/etc. At least in real-life card games you can trade cards (EDIT: hearthstone has dust - which acts the same).
That's actually rather reprehensible as well since the free loot boxes involve spending extensive time in the game grinding. These children are essentially Judas goats; living enticements to other children to join their friend in the game and possibly spend money.
They also had a PvP element where you could attack other peoples strongholds, but with the lootboxes it was also pay to win.
In France so presumably Belgium too, gambling companies are taxed on turnover.
Somehow though if EA, Activision, etc were taxed like slot machine operators then they would not be as inclined to include this stuff in their games.