The way progressive Judaism works (and I magine it would be similar for liberal Catholic churches etc) is that it takes emerging modern mores that its demographic identifies with, and then tries to find textual sources to show that these emerging mores are grounded ina historical and traditional Jewish approach.
So, for example, with enviromentalism and environmental stewardship becomng increasingly trendy and PC, people found the biblical commandment "Baal tashchit" (You shall not wantonly destroy) to attach to, and from this lone and lonely verse produced a huge megillah about how Judaism disaproves of plastic bags, 4 X 4s, printing out your emails and leaving the lights on (i.e lets perform a seris of tokenistic actions to show we're conforming to baal taschit even though the fundamentals of our lives, economy etc are still based on the basic paradox of being embodied - the need to destroy in order to sustain our bodies.)
In a similar way those against the brutalities of factory farming and cosmetic testing will cite the principal of tzaar baalei chayim. Those who are championing a sexual egalitarianism will cast around for powerful female prototypes in the literature - Ruth, Dvora, Yael, Sarah, rebecca , Rivka, Bruria, Rashi's daughters and grandaughters, and thoe who are championing socuial justice causes beyond the Jewish community can find a range of commandments and Tanachik verses which extol the virtue of protecting and supporting society's weekest members.
So what's wrong with this? Nothing in particular, except that its highly selective....all the verses and sources that don't agree with these modern mores are ignored, or have to be defused. So explicit prohibitions against same sex intercourse are recontextualised as only referring to promiscuousness, but monagomous ( or even better serially monagomous) relationships are permissable.
Other commandments are passed over as optional - for example -
To recite grace after meals (Deut. 8:10) See Birkat Ha-Mazon: Grace After Meals
or are ignored or disowned because they make detribalised Jews uncomfortable or afraid they will be accused of all the things Jews have indeed been accused of for eg:
not to intermarry with gentiles (Deut. 7:3) See Interfaith Marriages.
To exact the debt of an alien (Deut. 15:3) or, in plain English,
To lend to an alien at interest (Deut. 23:21) - although this is debated in the Talmud, in tractate Makot, where one opinion holds that the obvious common humanity of a Jew and a non-Jew means that ifinterest is regularly taken on a loan to a non-Jew, the lender may come to do the same thing with the in group, and expect interest to be paid by Jewish borrowers as well.
Other awkward anachronistic commandments are just ignored altogether, invisibilised, as their connection to modernity cannot be fathomed. For example:
That a eunuch shall not marry a daughter of Israel (Deut. 23:2)
That the woman suspected of adultery shall be dealt with as prescribed in the Torah (Num. 5:30)
That a widow whose husband died childless must not be married to anyone but her deceased husband's brother (Deut. 25:5) (this is only in effect insofar as it requires the procedure of release below).
To marry the widow of a brother who has died childless (Deut. 25:5) (this is only in effect insofar as it requires the procedure of release below )
That the widow formally release the brother-in-law (if he refuses to marry her) (Deut. 25:7-9)
Not to castrate the male of any species; neither a man, nor a domestic or wild beast, nor a fowl (Lev. 22:24)
This is understandable. people want to belong, and to reduce cognitive dissonance (disidents?) Secular Jews want to participate, do participate in the broader goings on of the cultures they interact with and are also part of. (Fundamentalist Jews, by contrast, have a much stronger pull towards their coherent in groups, and the loss of non-participation is easily outweighed by the sense of belonging and purpose bestowed by membership of the in group.)
This selectivity makes the progressive position tenuous, malleable, ripe with internal contradiction and arbitrariness so that each person does as right in their eyes, and religion is just called in to add weight and respectability to their personal proclivities (often shared by others who have similar proclivities).
Or am I missing something?