1. Games have always been trend driven. Assuming that means what I think it means.
2. Gaming trends are unpredictable as hell and trying to do so is largely pointless. Look at last year. Minecraft and Angry Birds were pretty damn successful. So were several FPSes and the Pokemon remakes. There probably IS an underlying trend there but good luck finding it.
3. Games are like 60 dollars these days anything less than stellar from any genre gets ignored because nobody can afford it.
4. From what I can gather the average JRPG lately has been pretty mediocre. JRPGs generally need to go out of their way to be fun more than your average FPS does because if an FPS is sort of mediocre, it's still an FPS. If a JRPG is mediocre, it's just a bunch of menus.
1&2)All you seem to have done is nitpick on terms I have used.
What I meant by "trend" would probably be better described by "hit". Similar to movies, only the hyped movies, well known and "cool" (again generalising) do consistantly well in box office. There are exceptions, like you mentioned, and I will liken those to sleeper hits in the indie movie scene.
3) What I meant by "anything less than stellar is not given that kind of attention by the fans". Is that anything less than stellar in the JRPG genre won't get the kind of word of mouth driven sales given to all the popular games selling today.
4) Is it really the case that comparing average JRPG to average shooter will have the shooter come out the better game? That seems exactly like the belief that many reviewers have at the moment. (I am seriously asking, I do not play a whole lot of shooters, but from my experience the average shooters I have played have been less than that.)