Dude of course none of them are 80 and over. These are mainly western Xbox reviewers (on metacritic). It would take a Final Fantasy for them to fork out a AAA. Most critics are complete blockbuster fanboys. They'll give out 100% indiscriminately to the GTAs and what not even though no reviewer should ever give out 100%. No such thing as perfection.
Now go look at the Famitsu reviewers. Different story there. The Last Remnant 38/40 (I haven't played this but WoW. Famitsu scores this radically different than the western reviewers have), Blue Dragon 37/40, Lost Odyssey 36/40, ToV and Eternal Sonata 35/40 SO4 34/40, Infinite Undiscovery 32/40 (Japanese critics liked it that much? Really?)
As you can see, the 360 jrpgs were critically well received by Famitsu. And of course they weren't going to hit it out of the park with sales but they were very respectable considering 1) HD Jrpgs don't sell there (WKC sits at 1st with 350,000 in Japan until Final Fantasy comes along) and 2) the 360 has a huge install base disadvantage.
Microsoft should not give up on Japanese games. Take a look at the library they have over there. They have lots of niche/quirky Japanese games (visual novels, shmups, sims, all sorts of stuff) exclusive/console exclusive to 360 over there. The 360 has a higher tie ratio than Wii and PS3 in Japan so it's obvious the 360 owners are enjoying the 360 software. Except for the Tales and Star Ocean fanboys who just bought it for 1 game. Those fanboys should play some of those quirky 360 exclusive Japanese games or god forbid be open-minded for once and try Halo, Gears, Fable, etc. And the install base is up to 1.1-1.2 million (way up from original xbox) even though the home console market is much smaller than last gen thanks to portables. Apparently the 360 has 8.5% of the home console market share. That is a huge improvement from last gen.