I do feel that Rosa gets the shaft a lot but she is quite important cause she (and most of IV's cast) are used as templates or archetypes by later games in the series. Most of the female leads in FF fall into her template and the only difference that separates her from them is that whereas it can be claimed she's the original and has her faults, the others are terrible in that they don't develop farther than the original.

I consider Rosa to actually have more going for her personality wise than Yuna or Aerith and even the few who do have a few unique niches they fall into ( Lenna, Rinoa, Garnet, and possibly Penelo) it doesn't change that they are still very close to the original. I guess what I'm saying is that its hard to slam Rosa for being a cliche when she technically started it for this particular genre.

Personally, I find Yuna to be more two dimensional than Rosa if only cause Rosa can fall back on two things: She started the cliche and technology limitations. Yuna has neither to fall back on. Even then I felt Rosa did more to show her strength and the fact that she wasn't smurfing retarded than other female leads. She follows Cecil even after he's exiled from his homeland, she forgives Kain despite his treachery, she guides Rydia despite only barely knowing her, and she follows Cecil to the bitter end of their journey despite it being a loss cause to begin with. She has devotion, compassion, and resilience. I can't see these qualities and still think of her as a mere two dimensional cliche. She may have never had much dialogue but her actions speak much louder than words ever could.