[totony]

I feel like Hearthstone is the outlier in your list

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).