I think they meant style wise. As it it was done to look like an anime from the 70s, and a lot of the bloggers and youtuber anime reviews are in their 20s or maybe early 30s. Thus, Space Battleship Yamato and Star Blazers is considered to be from, "the before times". And with some people, if it happened before they were born (especially in anime) they really don't care. Usually because it looks horrible to them (art and animation wise) or the plots are way too slow (which having watched the original in Japanese, I can say there are quite a few spots where the director spent way too much time on establishing shots and narration in 1974). However most of that was fixed for Yamato 2199. And it shows as the plot is farther along by episode 14 than it was in the original, and that is with at least two completely new episodes included into it.
A few older bloggers do remember Star Blazers and are either looking forward to this, or are already watching it. I myself am probably one of the youngest of the original fans of Star Blazers as I saw it as a two or three year old on televison during its first run. I know a few fans of it that are younger than I am, but they generally saw it on video or much more recently (I've inflicted it on a few people).
As for the other angle. Well that's probably a reason there is fanservice in the show at all. Though the closest thing to a loli on the ship is a 17 year old Yuria, which doesn't count. There is of course Hilde who is 13, but she's had few scenes and no fanservice, though she is getting a figurine after Yuki and Yamamoto. A few of the older female fans are a little upset by the new style fanservice (more so at the promotional material fanservice) and the lack of counter fanservice of the guys. Also the lack of older women. The oldest female we know of on the ship is Niimi, who is I think 27 years old. Though it can be said that there seems to only be maybe a half dozen to a dozen men on the ship that are over 30. And most of them are in engineering.
I agree on all points.
I was 7 or 8 when I first saw Starblazers back in the late 70's. Of course fans will be fickle about a lot of things like the plot to fanservice.
I like how the story has been expanded to explain a lot things that were missed, and how they removed the things that made no sense at all (Case in point the Pluto lifeforms). Addition of more female characters was a big plus. I think the reason why we do not see that many older crew members, except for the engineering section personnel that are experienced, is because of the aforementioned Izumo plan which was to escape Earth. Let the young live to colonize a new world.