Matsumoto should be in his '80s, so I don't think that he could have worked on this...and I understand that he was against a remake, which probably was led by monetary considerations.
"Why bother?" "because it sells" strikes me as a fairly acceptable reason, even when putting food on the table is not an emergency. The guy who owns the rights to the franchise decided to push for a remake while discussing the matter on his yacht, or something like that
Said this, If you would have watched/reads
Harlock and the rest, you would know that he mostly draws near-anorexic, androgynous human beings (or stocky warriors, or short caricatures like the doctor and the engineer guy, etc,). Women had gentler faces and hints of boobs. Fin.
This was maintained in the new series to the limit of the new key illustrators skills, even though I would like to know what causal relation you assume between "being Yamato" and "being designed by Matsumoto" (visual identity? I am quite literally not sure, whence my question). I mean, everyone looks like an edgy romantic poet close to death by starvation, in Matsumoto's works. The guy was really good at drawing ships and other mechanical vehicles, really. I honestly think that Toriyama could have drawn the series, as I identify the series with the "desperate fight against all odds" theme (trope, whatever), regardless of the its visual identity.
The CGI is not too terrible, even if I recall at least one poor /jarring integration between CGI and 2D per episode. Considering the rubbish you can get in series with smaller budgets, this is not a bad result, and one I can accept. Much like visual identity, I am not really bothered by CGI, as long as it's not hideous (I only watch anime, so my standards should be really low!).
The story...sorry but I will just say that the relation between cast number and fucks given depends a lot on the viewer's patience. You don't really want me to consider this as a valid argument?

But honestly, I found the original story embarrassing when I saw the series as a kid. The new story does a better job of connecting
Yamato with the SF themes of the time, and as far as I know it is also closer to Matsumoto's vision (he may be a reactionary, but precisely for this reason he does not seem to see the world in black and white terms, to simplify a lot).
A clear problem is that even with a fairly sizable cast, the first cours of the series (episodes 1-11, really) need to procrastinate on small stories to fill up a 24-episode slot. This is a standard problem of anime in particular, and of comics (yes, western ones too)/series/etc. in general. I would go and say that this is a problem of "modern writing" in general: say,
Ashita no Joe and the classic
Star Trek really revolved around 4-5 characters, and with ease. Most call this "decompression", and credit none other than Tezuka and (Stan) Lee for introducing it in comics/anime/manga/whatever. I don't recall the old series to have a smaller cast or a faster pace, though.
EDIT:
Akira and
Nausicaä also have one kazillion characters...for widely praised series, they certainly went wild with the amount of characters sprawling through the narration and at times disappearing into nothing. Writers who can keep the numbers down also usually work on closed series and less chaotic deadline systems than anime/manga ones. I am fairly sure that somebody (an anthropologist at MIT, I kid you not) wrote a book about this. Not sure what to write about? Add one more character, it can be killed off later

"The only desire the Culture could not satisfy from within itself was one common to both the descendants of its original human stock and the machines [...]: the urge not to feel useless."
I.M. Banks, "Consider Phlebas" (1988: 43).