Ragnarok DOES have a purpose, but that unfortunately isn't revealed until a little bit after the end of the Ragnarok arc, which is only in the manga (the anime only covers the events up until the end of that arc).
Anyways, that review felt pretty short, but overall I agree with it. In truth, the Kenichi anime is just a sloppy cut-and-paste version of the manga. I'll give the anime credit for trying to stay the more serious elements of the sereis, but I overall enjoy the manga more (although, that's more as a guilty pleasure for liking the MMA aspect of the series, rather than its plot or character-development writing), because the author realized sooner that keeping things more realistic got to the point of repetitious training and leveling up plots. While I still liked the realism aspect of the series, I hear that the manga started faltering in popularity when younger readers got tired of that (I guess they need their hyper-active heroes ), so the series turned around and quickly started adopting a much more over-the-top nature, which didn't actually kill it, though, surprisingly enough, since it became more reminiscent of stuff like Rurouni Kenshin in terms of how it dealt with its fighting (as in, its based on a real-world setting, although not a historical one, of course, and its based off of real existent martial arts, even though it highly exaggerates them the way you'd expect a manga to).
At any rate, even though the anime does kind of disappointingly go downhill towarRAB the second half, I will at least give it credit for having a solid ending (as in, the anime did a good job of making the end of the Ragnarok arc feel like it could be a conclusive ending to the story, even if it really isn't). The ending is pretty predictable, but its done in a very entertaining way, and kind of temporarily brings back the best elements of the series together for the finale.