Jirachi needs better lore integration. It's just kinda there and a Legendary should never be "just kinda there" especially a Mythical.
It actually gets a tiny tidbit in Alpha Sapphire. You can find (text telling you that you've found) a picture depicting Archie, Shelly and Jirachi at the tanabata festival. There's no equivalent for OR, oddly.
Jirachi has a sort of gimick in that its the official event pokémon of the tanabata festival, and one with a special move is given out every year since 2013 in japan.
Of course, none of these ever make it out of japan, so we're lacking Jirachi with any of Follow Me, Heart Stamp, Meteor Mash, Play Rough or Moon Blast.