Fights in 1.0 definitely had HP phases yes, but those phases more often than not just added more moves to their available pool. There were certainly still fights with "Stand here and wait for X" mechanics but even Ifrit in 1.0 could repeat certain sequences of moves back to back instead of being wholly predictable (See: Multiple dash phases or back to back eruptions)
More often than not you were learning how to deal with specific moves in general because you weren't able to predict exactly what move was coming at what time, you just had a rough idea of when certain moves where in the bosses available move pool based on HP phase, with the exception of large signature attacks that had set points.
I would argue the stakes are already high and foster this currently.
The loot system guaranteeing a drop of some kind combined with a strict rotation for most fights is promoting the attitude amongst players that because X member caused a wipe due to something that the rest of the party knew fully well was coming, either from lack of knowledge of the fight (didn't watch a video) or poor mechanical ability (bad) on that player's part, that now that 1, 2, or w/e number of players that messed up have now "prevented" the rest of the party from getting something. It becomes very easy for the party to quickly turn on players they feel are under performing or aren't learning the rotation fast enough.
This is very different from genuinely getting rocked in a fight because eruptions or dashes just happened 4x in a row, the anger is now directed towards the boss "Well IFRIT screwed us this run, lets try again" The blame falls on the boss or the mechanic and the party is less likely to turn on each other.
EDIT: adding to the last part.
The situations mentioned above (Ifrit 4x Eruptions or dashes in a row etc) are often survivable with player skill as well, if players are taught to deal with the possibility of varied mechanics etc rather than just waiting for the next ability in the script, seeing this happen in one fight might fully prepare them for the possibility of it happening in others so the mentality will develop to watch out for that sort of thing.