[Matrixbeast]

It was a facade when he said he didn't care about Earth. I pointed out that he did come to eventually like the planet. It wasn't exactly a character defining moment, though.
Gai's character type wasn't grating to me (Remember, I'm the one rallying for my Shunpei in Wizard), it was more that he never grew out of it or toned it down.

And if I recall, during Barizorg's final fight, he was taunting Joe that he could never live up to Sid was a failure.
But the problem wasn't that Barizorg couldn't be turned back, it's that he was that the revelation that it was irreversible came so early that it practically ended all resolution for Joe.

And let's hope you do. Gekiranger deserves the love.