This question could seem as an opinion based question, but let me try to explain why I think it is not. In Dragon Ball, Goku was supposed to be completely pure-hearted to be able to ride the Flying Nimbus, to the point he needed to have no bad intentions at all, otherwise he couldn't stand in the top of it, he had to be a sort of Super Saiyan Jesus. At some point in the Dragon Ball series, Vegeta emphasizes this by saying Goku never dared to kill someone (because of this).
But at some point after that, Goku indeed kills someone, that is kid Bu. With Piccolo before, someone could argue he didn't actually finished him because he immediately reincarnated or so, but this isn't the case of kid Buu. And now, in Dragon Ball Super, Goku is doing something different to what he always did. When someone threatened the Earth or the universe, no matter how strong he was, he at least tried to defeat him. But with the case of Zeno, he didn't even try. Someone could argue Zeno is so powerful that he knew he couldn't defeat him, but is Zeno that powerful? He isn't almighty because several Zenos were created by Trunks and Zamasu when messing with time, Zeno isn't unbelievably strong because he can't follow Dyspo's moves. At some point I thought this "destroying all universes" thing was a fake, but now the manga has shown that
indeed Zeno destroys all universes permanently and the great priest doesn't care, he only acknowledges Zeno whims.
Why Goku didn't even try to defeat Zeno by training and merging with Vegeta or whatever, and he doesn't care much about all the universes which are being destroyed every time he defeats them? Is Goku still pure-hearted?