I think that J cabins across many global airlines have caught up with more of the mainline carriers in the past few years and are of a critical mass to go and review, versus a bunch of "I can't believe JL still uses recliners on their 767s!" type of reviews that would've resulted only a couple of years ago. Lots of innovation in the J space.
And, for the record, J on the JL 767 does indeed suck.