Sanji has had plenty of epic moments since Thriller Bark up until now. Whine whine whine Kishido, that's all you do when it comes to Sanji. It's like it's your own pride that's hurt when Oda puts the joke on him. He threatened Jinbe and can fly, the dude is awesome!
Read the first 2 panels of this page please:
http://www.mangareader.net/one-piece/629/11
This was, since the time skip, the only real badass moment Sanji had. And by badass I don't mean giving people mean looks or defending ladies. It's "badass speech Sanji", the voice of reason within the crew.
Enies Lobby, Water 7, Baratie, Thriller Bark. He had countless of cool moments and that was why he was always one of my favorite characters in the series. By far.
Now I would like you to read the rest of the page. The only moment of real badassery destroyed by turning this scene into comic relief. There is nothing wrong with abusing characters for giggles, but especially Fishmen Island overdid it. Hard.
And now we have a Sanji who rages at anyone and anything, even kids these days. This weird rage attitude robs him of his coolness, and this is my biggest problem. Call it character development or whatever you want, but Oda is sacrificing Sanji for storytelling purposes.
Edit:
Or to sum it up like Choperman:
Yeah true, he's been getting increasingly annoying, okay I see your point
I still somewhat hope that his odd behavior is an after-effect of his time with the Okama's, and that he will return to his old self soon.