The decision wasn't mine to make, and I've advanced your exact points previously to the development team. Auto-rating in PT2 was always cash only, and adding tournament support would be a new feature. I agree that for SnGs there are enough regulars that it's probably worth it, especially if (as I've also been hoping we can eventually do) we can one day change the player's icon at the table (e.g. I don't know what his stats are, but he's a fish for sure
Total real $ won, number of tourneys played and average placement aren't yet available in PT3's HUD. This has to do with the way these statistics are structured, but I'll make sure this feature request makes it to our developers.