Falcon can punish too, though, arguably even better than Ganon since he's faster and has such deadly combos. He can also create opportunities, which Ganon has trouble doing. Hence why I see Ganon as basically just being worse Falcon. I mean sure, he has better tech chases, but he has trouble initiating those tech chases, and who needs to chase when you can just kill people off a single throw as Falcon anyway?
I actually feel a projectile would help Ganon a lot. It would either force people to approach him, thereby removing his difficulty in getting in (if you can't come to them, make them come to you), or alternatively it could put pressure on the opponent, forcing them to deal with it in some way that creates an opening for him. He also uses a lot of projectiles in the games, and it would help differentiate him from Falcon a bit more.
Also, they created Solarbeam for Ivysaur, and Brawl- gave Ganondorf a projectile. It's got to be possible.