I think it's obvious. Canha draws walks, Hiura doesn't. Canha has a career OBP just shy of .350. Had a 122 OPS+ last season and had a 101 OPS+ with the Mets before the trade this season. If he can get back to that 100-ish number with the Brewers even better, he's not that far off in a small sample.
I don't hate Hiura, I was all for using him to replace Winker much earlier on, I think he just got injured at the exact wrong time, a time when I think they may have finally have given him his chance. But I also don't think that the call ups the Brewers have made even before the trades are definitively wrong.
If this thread has a flaw, and I'm on the side that believes it does, it's that folks arguing for Hiura aren't acknowledging the logic in some of those other moves. I understand wanting your guy, there are logical arguments to support Hiura, I just think it's evolved into a more emotional mindset as time has gone on.