The benefit (to the polemicist) of minimalism (the former approach) seems chiefly to be that the complaint is left intentionally "fuzzy", which fuzziness allows those sympathetic to the general thrust of the complaint both to fill in details as they see fit, but also to facilitate disdainful posturing towards persons wishing to see a more sharply articulated criticism. The idea here is seemingly to present the criticism as being so obvious (and so obviously correct) that any protest concerning the vagueness of the presentation is the product of either willful blindness or stupidity.
Alternatively, the primary appeal of the abbreviated-dense approach seems to be to try to psychologically overwhelm any would-be detractor, giving the impression that the mountain of evidence in favor of the (still usually vague) complaint is literally insurmountable.
Here is an example of an abbreviated-dense Facebook polemic:
(Arguably, this particular specimen adopts a composite strategy, with it's minimalist header ("MARRIAGE =") followed by a deluge of additional text. However, I will here ignore the header and treat this exclusively as a species of the latter type - as given, above.)
Here one can see the "density" in terms of the number (given the size of the image) of proper names, common names, and descriptions. And one can see the "abbreviated" nature of the enterprise in terms of the slipshod "citation" effort. (Namely, there was some attempt to provide bible citations for the material deemed relevant by the author. However, this attempt was incomplete or halfhearted in that the author provided no citations at all for one quarter of his or her introduced categories.)
Characteristic of the image-slogan polemic form (and, indeed, arguably characteristic of polemics more broadly), however, is the absence of substantial argument. I presume that the general form is supposed to be (something like): 1) "marriage" equals a, b, c, d, e, f, g, and h; 2) a does not equal b; a does not equal c; [with the non-equivalence demonstrated recursively]; 3) therefore, "marriage" cannot equal ab, c, d, e, f, g, and h.
Intuitively, the author seems to want to make the point that "marriage" is a wooly notion. Perhaps, this point can be intelligently pressed. But, the above digital doodle is not a suitable vehicle for this effort.
First, this polemic fails to make one fundamental distinction: reports can be descriptive or prescriptive. It can be truly stated that the Bible accurately reports the (shall we call them) "marital circumstances" of numerous persons. However, in several of the categories depicted (e.g., Genesis 16 regarding "man + woman + woman's property" and "man + woman + woman + woman..."; etc.), these reports are plausibly merely descriptive and do not constitute endorsements of the relevant actions. The Bible describes what these people did. But this does not amount to a Biblical prescription for marriage that is an alternative to the clear prescription in Genesis 2 (|| Matthew 19).
Second, the caption speaks of "illegality". But, number one, at least three of the categories depicted aren't obviously illegal at all. For example, "man + woman", "man + brother's widow", and "rapist + victim" all represent circumstances that are not obviously illegal. (For sure, a rapist is not, in our legal system, required to marry his victim. But, this says nothing about it being illegal for a woman to freely consent to marry a man who had at some past time been convicted of raping her. It is surely highly implausible that such a situation would obtain. But, "implausible" and "illegal" are not synonymous terms.)
Number two, two categories that DO arguably depict illegality (e.g., "male soldier + female prisoner of war" and "male slave + female slave") do so in virtue of depicting actions that run afoul of laws other than marriage laws. That is, the soldier-prisoner example is not illegal because it violates marriage laws; it's illegal, when it is, because it represents violations of the laws of war. Likewise, the male slave-female slave example is illegal because of the 13th Amendment, not (in the first instance) because of a particular marriage law per se.
To summarize, and expand slightly: Three sorts of "marital circumstances" depicted are not illegal at all. Two sorts are illegal but for reasons other than marriage laws. And three sorts of "marital circumstances" are illegal, and are illegal because of marriage laws (they represent cases of polygamy or, maybe, polyandry), but in these cases, the Bible apparently only describes these "marital" arrangements, it does not obviously prescribe them. Hence, even for the uncontroversially maritally-relevant cases, the Bible itself could be rightly said to describe persons and circumstances that violate prescriptions that are set forth elsewhere. In other words, the Bible itself arguably indicts many of the characters that appear in its narratives.
This instance of Facebook polemics will doubtless excite anti-Christians to "hurrays" - or rather "Likes." But, although the author would probably bristle at the idiom, this excitement indicates nothing more substantial than an exercise in what (when Christians are the culprits) would unhesitatingly be called shallow, unconvincing "preaching to the choir."