Ho-oh Movepool usage

They already nerfed the base stats to rein them in, so they wouldn't make Sacred Fire as a strong overpowered move like Frenzy Plant or Blast Burn. If anything, I'd worry they would choose to make it even worse than Fire Blast so no real point in adding it.

Game Balance. If they gave Ho-Oh Fire Spin/Overheat, or Air Attack/Sky Attack, it would dominate Fire or Flying respectively. The same reason that Mewtwo has Psychic instead of Future Sight, that Rayquaza has Aerial Ace instead of Sky Attack, and that Tyranitar doesn't have a Rock fast move (until next month, we all think, anyway). If the very strongest pokemon had the strongest moves, there would be no reason to use anything else in battles.

Sadly, this is the way of the game. Anyone used Arcanine against serious grass recently? Or Starmie against serious fire? Didn't think so. The threat level will continue to escalate, and they will continue to tweak and rebalance so that there's always something to go after, something better than anything you have.

I mean, with the Lati twins and then the Regis coming (we think), I'm kind of bored with Legendary raids. After the weather trio, everything else seems just so ho-hum. What I'm excited about now is double Rock Ttar and Dialga and Palkia and Mamoswine and the next big thing, not the current so-so thing.

I actually kind of like the idea of 'extra' moves, moves that can't be learned when you catch the pokemon, but can be learned by TM. An interesting mechanic that could open up some other possibilities. Or maybe a special TM that lets you get these extra moves.