Reading the article, it somehow baffled me how much work and thought they actually put into this. Like it mentions meetings, wow.
For many new cards, I get the feeling they really don't mind making them too strong. Similar thoughts when I look at the fanbase.
I (also) enjoyed the game when playing a 3/3 bear on turn 3 was nice. Now you sort of have to expect an indestructible hexproof creature with maybe even more abilities, for 2 mana, to be deemed playable.
Rambling off, sorry thanks.
By which criterias/standards do they make these cards, and evaluate later wether they need to be banned or not?