The people using that term to describe makeshift hospitals want their listeners/readers to draw that connection.
By whom? Who tells you the speaker considers their association(s) relevant? They are not entitled to assume those associations outside their own mind (and even inside it, that does not seem proper mental hygiene nor proper process).
> The people using that term
False. /Some/ people - irregardless of the number - use language that way. Other people do not, and hold that treatment of language in contempt: they do not care about "familiar" language in which a clan of two or two billion decide that they will interpret some term in some way specific to them. (What does 'familiar' mean just a few terms earlier?)
By people who speak the English language.
The reason why people are calling makeshift hospitals "concentration camps" is precisely because they want their listeners/readers to think about Nazi concentration camps, and to recoil in horror. If you look at the specific blog we're talking about, they use terms like "deportation," which are likewise meant to make people think of the Holocaust.
This is a common rhetorical tactic, and it's not limited to the term "concentration camps." During the pandemic, opponents of vaccine passes and testing requirements have frequently compared these measures to measures taken by the Nazis.
As for your talk of "clans" and such, I'm a bit puzzled as to what you're talking about. Language is a means of communication, and it's clear that this blog is trying to communicate the message that sending people who test positive to makeshift hospitals in like the Nazis deporting millions of people to concentration camps.
No, really not. I do speak it, and I surely I would not use it that way.
> If you look at the specific blog
If you believe that the author of that page was being manipulative, I will not argue - I don't know. If you are sure of that, I hope you are on solid grounds. But in general, when somebody says 'deportation', that is meant to mean some meaning in the cone of "deportation" as a function of the context - not "the statistical mode in the set of interpretations that a mesmerized mind crippled to passivity has emerge in a game of associations".
> I'm a bit puzzled
If you chose as a name "Diogenes Kynikos", you should consistently be wary and distant of what people in general do and think. If one does, like Diogenes Kynikos does, others will too, surely. That rules out that language could ever universally be some "game of associations", as some surely would not participate to it - Diogenes would not. And cultural differences suffice to break the possibility of relying on cultural associations (outside the manipulation of specific targets by malicious agents) - you cannot know if your listener is part of your "clan" and shares your metaphors, the "language to understand each other in the family". And this is part of why we do not rely on cultural references in our expression.
Also, we would not because language intended to be evocative of emotionally charged images would be, immoral (emotional manipulation is immoral). So, no, normal people do not speak that way. Malicious agents could - only them actually.