I didn't say it was random. On the contrary, I'd expect it not to be. As you say, humans are bad at random, so if you told a human to sit down and write nonsense content in a nonsense script, you could probably expect some structure to emerge despite the lack of meaning. The writer might even accidentally inject unintentional interpretations by semi-consciously templating their work off of familiar texts.
It’s not random. The distribution of words obeys the Zipf’s law. A random generated structure would not look like an written real language.
https://skeptics.stackexchange.com/questions/6085/has-it-bee...
According to [0], "A long succession of (actually pretty good) past statistical studies has revealed that Voynichese has an abundance of mechanisms that give it internal structure, not only in terms of letter adjacency and within words generally, but also within lines, paragraphs, and pages."
Whatever process generated that structure, it seems like it required more work than is necessary to achieve the aim you suggest the writer(s) had.
[0] https://ciphermysteries.com/2016/01/21/voynich-statistics-an...