So to start off, can you agree to the position that while time does not equal quality, more time can lend itself to making a more fleshed out argument? For one, the investment of time between making an argument like "RWBY is bad at social commentary because of the White Fang Arc, period" and "RWBY is bad at social commentary because of the White Fang Arc, the hypocrisy of pushing the 'fascism/authoritarian bad' theme with Atlas when Coco Adel (based on and written more and more like a Nazi) exists..."
You're essentially making the same overall point in both, but there are likely to be more reasons laid out as to support that point in the latter version.
More time absolutely can be used to better flesh out an argument, but just because you’ve taken a lot of time doesn’t inherently mean you’ve actually said a lot, and it’s also important to recognize that there’s absolutely such a thing as too much time as well.
For example, the average TED Talk is around 18 minutes long because TED organizers determined that 18 minutes is long enough for a speaker to flesh out an idea, but short enough that a listener could take in and understand all of the important information. When you say, take 30 minutes to an hour to critique a title crawl opening of a 2.5-hour movie, people will start getting annoyed and want you to just get on with the point. Whereas an argument made in 5-10 minutes certainly isn’t as ‘fleshed out’ as the hour long one, it’s gotten the point across and the speaker can then move on to their next argument and keep their audience’s attention. It depends a lot on what your content is, but this is just how presentation, public speaking and the human mind work.
Yes, you’re second example is more fleshed out, but just because you’ve taken more time to explain it doesn’t make it more ‘objective’ than the first. All it is is a decently supported opinion. And like all opinions, people are free to agree or disagree with it. Some could argue that Coco is a minor side character(in the show at least and in the books is written by someone else), isn’t written much like a Nazi at all(at worst she’s a pervert), and isn’t in the Atlas Arc whatsoever. Of course, people being uncomfortable with Coco’s kinda pervy characterization and inspiration is perfectly fair, but that doesn’t necessarily mean everyone else will have that same problem.