I can see certain bosses giving a JRPG newcomer some trouble though, Yunalesca is especially nasty if you're not prepared for their gimmick, so depending on how much trouble certain bosses give you the amount of cutscenes you'd have to sit through all over again will certainly add up to more than 40 hours. At least Persona lets you fastforward. But yeah that is actually a bit on the long side, I was just thinking from the perspective that they're not that difficult and easy to get the hang of. Persona 4 in particular was my introduction to the SMT franchise.
True, I wasn't thinking about the difficulty of some bosses. FFX was more or less my first, but I remember getting stuck on a boss and putting the game down for a long time.