Hearthstone is not trying to be as complex as MTG, and that's fine. The program follows the rules exactly, which is also fine. What annoys me is that it's up to the community to find out all the rules edge-cases by reconstructing them from gameplay. It also doesn't help when the unwritten rules can get changed periodically (e.g. for the old Warsong, it used to give Charge before Battlecry, then it was changed and marked as a "bug" for several months.)
In MTG, the comprehensive rules aren't meant to be read, they're what you refer to as a last resort. Hearthstone doesn't need comprehensive rules, but it's very annoying that the closest thing to an advanced rulebook comes from the wiki, and that people have to tweet developers to ask rules questions about newly revealed cards.