I, as a person that has parsed every fight (over 50 battles in VWNM higher tiers each week) with the strongest players in Lunarians LS for months, I can attest that this nerf was highly needed. I do not think that Tanaka is doing a poor job in game balancing and the game is actually going in a good direction. Here are a few tidbits of examples of how this is so:
Lv95 Ukon vs Lv95 Amano parse:
I was disillusioned after seeing this parse. Both players have the best gear for their respective jobs and both are very skilled at playing. I tried my best to find out where amano stood by eating Red Curry Buns and doing my best in DD. After seeing the parse result, I found the result: Amano + Ukon was tied. However, it turns out that the lv95Ukon wasn't eating food or using a TP set because he was too lazy to change gears. He was using a P.def set with Twilight set only.
When someone noted that he was parsed and was on par with a 95amano, he ate food and started to use a TP/WS set. At the end of the Qilin battle (without using 2 hours), he was a full 12k damage ahead of me, and over 30k damage over any other DD.
What this nerf will do is put WAR back as a top DD, but not overwhelming as it was before. It is also unknown what the 99 relics will be capable of. Perhaps at 99 there will be something else for WAR.
Tachi: Shoha is not as strong as people make it out to be. By comparing to Abyssea mobs (OMG THIS GUY GOT 7K IN DOLL PARTY) is ridiculous because any other DD such as a Kannagi NIN can do the same. Also, in order to get these insane numbers, the SAM typically has to save TP up to 300TP which is losing 2 WS's for the price of one big e-peen value.
I have parsed the same with 5/5 Tachi:Shoha with one of the best Apocs I know of with Entropy 5/5 and the parsing is close. Apocs are still top gun-- we just see too many sucky ones. Right now, Ukon and Tachi: Shoha are very similar in playing field with still advantages to Ukon. I don't think that this nerf will make ukon obsolete. I do know however, that there will be more bandwagoners for SAM again because just about "Anyone" can get this Reliclike damage WS. But either way, the well geared relic/empyrean wielders will likley win anyway.