Japan still loves the JRPG genre, and it's already demonstrated that a new IP can sell better on the PS3 than an established franchise on the 360...
In the West, it's not that people don't care anymore about console JRPGs, the thing is that the great majority of console JRPG lovers that have a PS2 have decided to go Wii, go PS3 or stick to the PS2, only a little portion of the fans have a 360 (while the great majority of 360 owners are western-oriented fans, especially of the shooter genre), the only game that is selling really well is Lost Odyssey, and i wonder how much the game would've sold if the cover didn't have "From the creator of Final Fantasy" (i think the game is good BTW)...
Meanwhile the franchise that always brings the JRPG boom in the West since the PS1 era is absent, we still don't know about a release date here, hell we don't know a Japanese release date, FF7 was ready 2 years into the PS1 lifespan, FF10 was ready A YEAR into the PS2 lifespan, the PS3 already has 2 years and 4 months in JP and NA, and 2 years in EU, by the time FF13 comes out in JP it will be 3 full years, and in the West it probably would be 3.5 to 4 years, that's not helping the genre either...
So my point of view is that the 360 getting the JRPGs is not helping the genre, but it's not the only problem, this gen has a lot of issues that last gen didn't have (like console western-oriented fanbase growing, the PS3 not being dominant, the Wii not being 3rd party choice, the 360 doing all the deals and the handhelds getting main games like DQ9), this caused a lot of confusion, now the genre is still viable, but the companies (from consoles to software) have to wake up of this mess they have caused...