Turning your opponents Vapor Snag into a Flusterstorm is not a good feeling, and so one can see that there are real things holding back an Infect player
It's intended to make playing with the new cards more fun by clearing up the common misconceptions and confusion inevitably caused by new mechanics and interactions
They are really hard to pull, but even then, some of them might not be rare in terms of price, as these are determined by various factors such as the art, the usefulness, or the Pokemons popularity
To put that more plainly, let's think back to the original Blastoise cards
Imagine attacking into an empty board just to be surprise-blocked by an Emrakul and a Griselbrand
Reveal Lands Enters tapped unless you reveal a land to your opponents that has a type from either of the mana it can produce