Starstorm was introduced and given to Poo. Starstorm is thought of as "Poo's move" - was introduced for Poo, and is arguably more significant to the plot than any PSI move in the entire game, since his moves are the only ones that are plot-introduced.
The fact of the matter is that abandoning most of the most well-known PSI moves would be idiotic. Using the same moves and making them different is taking two steps forward, one step back. What is accomplished by forcing the characters to be similar despite the fact that your idea that using anything other than what he learns in the game is blasphemy.
Basically, the reference would be "Here's PSI Rockin', the cool main attack of Ness' that emits a huge blast of hexagon-shaped energy. And PK Love? Well, same thing, except different effect and it's Lucas', yeah yeah". Starstorm, Fire, Freeze, and Thunder are more interesting references, and forcing references to a move twice would be idiotic and a waste of time and space if they're going to make it a completely different move anyway. PK Love and Rockin' would share one trait - they'd be a fancy wall of hexagons. Different effect perhaps, different shapes, completely different, but people would notice that they're the same moves in spirit. Starstorm would be unique, no one, under any stretch of the imagination, could say "Starstorm is too similar to Rockin'!", because it's not. Fun > "Staying true to the source material". The only reason you want to apply this imaginary rule to Ness and Lucas is because of what fanbase you participate in. If you were Zelda fans, you'd want to give her at least made-up moves. If she didn't have any source material, she may as well have gotten the Hammer from LttP.