Sorry, but I have a different view. I can understand this perspective after Thousand Suns. But to me great bands experiment by taking risks and trying new styles/ideas, while still retaining their core 'essence'. Probably the classic example of this is the Beatles.
Thousand Suns was a concept album, and it was great they took this risk. But risks sometimes don't quite work, and in this sense I can understand this view if one was not that happy with Thousand Suns compared to their earlier releases.
But...now with Living Things...they have reached new heights. This is their best so far, where they both have songs more like their earlier songs, and also have continued to venture into new areas. In particular, Roads Untraveled shows a true maturing of the band by delivering a superb song in a new style for them.
Just my thoughts...