No they are very rare, sounds like you are just unlucky.
Frontier implied that they would, but the consensus over on the mining subreddit is that there is no long-term depletion of hotspots. Since the game does track exploded astroids, it's possible to run out in a local high-traffic area, such as around an asteroid base or at the center of a hotspot. But as far as anyone can tell, the exploded 'roids reset after several days (exact period uncertain) and there is no long-term decrease in the number that are crackable.its possible the place you were mining has been depleted by miners before you
the game does actualy keep track of how much resources are left in a ring.
but it can take months for it to hit 0
I heard it was three daysthe exploded 'roids reset after several days (exact period uncertain)