Magic_Of_Light: RPG stands for role playing game. It is a story driven game, where magic, weapons, and training will make you stronger over time. Some people call mass effect a shooter, because it has shooting elements. But the core of the game is rpg, just as it is with skyrim and oblivion. Action combat does not make it any less rpg than say wizardry 7 with its turn based combat.
There is casual rpg, and action rpg, and strategy rpg, and shooter rpg, and first person rpg, ect ect ect. But they are still rpgs. Just because they arent your style doesnt mean they are not rpgs. You just prefer the casual or strategy kinds like fallout, or baldurs gate.
Just to solidify my point here, here is a list.
https://en.wikipedia.org/wiki/Action_role-playing_game#Early_1980s They date way back, its not like its new.
Going by your logic the legend of zelda was not an rpg. Even though you grind for money, buy things, collect health magic weapons, find secrets, battle bosses, ect ect. Adventure rpg, action rpg, rpg is the core mechanics of how characters progress, not the combat alone.
Whether a game is story driven does not affect the genre, nor do magic (absent in Wasteland/Fallout), weapons (absent in Quest 64), and training (absent in Legend of the Ghost Lion) define the (game) genre of a game. On the other hand, the main gameplay style (in this case, turn-based menu-based combat) *is* what defines a genre. Therefore, action combat *does* make a game not an RPG; said games are action games which just happen to have borrowed elements that are commonly seen in RPG.
With your Zelda example, I have never considered any of the games in the series to be RPGs; they're action games with some adventure elements. (I note, in particular, that "find secrets" and "battle bosses" aren't even RPG elements; finding secrets is native to the Adventure game genre (but it widespread in other genres; even Super Mario Bros. has secrets to find), and boss fights are extremely common in pure action games). Also, I believe the original Space Quest has you grind for money at one point (saving in case the slot machine decides to annihilate you).
The progression mechanics are not a factor in the genre at all. I could point out that, for example, in Touhou 12.8: Great Fairy Wars, you level up by freezing enemy bullets, but yet nobody would think of that particular game as an RPG. Then there's also Ghost Lion, which I mentioned, that lacks typical RPG progression mechanics but is still an RPG. I could also mention Wizardry 4 here, for another example of non-RPGish progression in a game that is generally considered an RPG.
One more thing: My classification of games is not related to my preferences. For example, I definitely enjoyed Shovel Knight, which is a game that people tend not to classify as an RPG. I also have Crimzon Clover, though I have never finished it. Also, challenging turn based RPGs are definitely *not* casual; just look at the Wizardry series, for example.