I would agree with your statement. Though I would point out the reliance on plot and its quality for Jrpgs. A traditional Jrpg relies more on its plot, characters, and storyline progression than any other title currently on the market simply because the entire game is centered around the plot and aspects within it
No, I mean for a game that relies heavily on plot, it's really hard to judge the quality of the plot until you've gotten quite a few hours under your belt. So instead of going into a game and expect to be dazzled by the plot, I always put gameplay first. You can get a pretty good feel for the gameplay after like 10 minutes into the game. Usually, if the gameplay is good enough for me, I can worry about the plot later.
Summon Night 2 is the perfect example. The gameplay is fairly decent after 5 minutes of playtime, but it was only after maybe 8 hours did I realize the plot is getting nowhere. The characters are interesting enough and the gameplay doesn't make me want to kill myself, so I kept playing.
Like I said, you guys should try Nintendo's Fire Emblem series. It's a brutally hard strategy rpg, with some pretty amazing stories. I was introduced to the series by a friend. The games usually keep you in a world for 2 games before moving onto a new story about a new continent. The plots sometimes share the theme of humans battling with dragons, but the true depth isn't revealed until you play the game. You even get to see your favorite characters and their relatives/off-springs/older/younger self in another game. It really adds some much to the plot and characters. Like Karel from FE7 (first US Fire Emblem) was a crazed killer who lusts for blood, yet in the original prequel, he's older calmer man who is at peace. Yet again, in one game, you will witness Karel's younger sister and how she fell in love with a man, while another game, old Karel will be talking to his brother in law and his niece. Just seeing characters in completely different stages of their lives help develop them better than most games.
The series has developed villains so brilliant that you even feel for them. There's not a bunch of emos running around with their angst. In one game, one of your characters gets killed by the villain of the game. The character the prince of Lenster who is well loved, and has a strong sense of justice. Sounds a bit typical, but then you find his other flaws like his seem of pride and holding onto a grudge from 100 years ago with a rival nation. The rival nation Thracia is depicted as a war loving nation who'll fight for money, and their king is a ruthless man. The flip side is that this nation is an extremely poor country where crops can grow, so they fight as mercenaries to make money. Thracia longs to conquer Lenster for the fertile soil, while Lenster holds onto their 100 year grudge and withheld aid to Thracia. The ruthlessness is justified and you can't help but be angry when your character is killed, but also feel sorry and understands where the other guy's coming from. That's how powerful the plot is in Fire Emblem. Bad guys aren't really bad guys, just a different point of view.