There are other ways to have conditions removed than esuna.

Who won't take swiftcast? Protect? E4E? CS? Largesse? CS? Lucid Dreaming? They could just as easily build that into each class, rename it, etc.

Oh no! It looks like I can't take all those skills at the time. Guess I've got a.choice to make depending on the encounter. Let's be honest, this is a huge step up from the cross class system. Role skill choice actually mean something. If you personally feel like you must have esuna all the time, by all means take it.