Why?
They are at least as biased as radical feminists (if not more so).
Religious officials and spokesmen by definition have a (religious) agenda.
Why
For the same reason that you would want to go to evolutionary scientist to learn about evolution more than you would want to go to the creationist. It is not as if either does not have an agenda, but the evolutionist lives and breathes and drinks and poops evolution. They read every article, and think deeply on the subject, and immerse themselves into the minutiae to an extent that evolution’s greatest critics never would. It is their life. Torah is the life of the rabbis to the exact same extent.
You seem to be interested in the Old Testament, as you are continually referring to it, so why not at least refer to the people that have studied the Abrahamic traditions from the inside out, rather than those who hardly even touch the book other than to cut and paste its supposed shortcomings.
Like young earth creationists normally only deal with the science in as superficial a manner as possible, so too do secularists treat the Bible and the “Abrahamic faiths”.
So lets look at the Abrahmic faith then. In terms of Abraham himself, this means that not only did God forewarn him in a dream about the path that Sarah was leading him on when she treated Egyptian Hagar as just so much chattel. Moreover, when Sarah puts her lowly ‘female incubator’ l under her thumb like so much chattel, so to did the Egyptians put Sarah’s progeny under their thumbs, like so much chattel, to let them understand the world from the point of view of the Egyptian chattel, Hagar.
This point made by God to those who actually study the Abrahamic faith was not even subtle. 400 years of slavery and oppression later, it was driven home with an iron fist.
“You want to treat my girl Hagar as chattel? Fine then. The lowly will be raised and the high and the mighty will be humbled. That is your ‘Abrahamic’ justice, my dears”.
The radical feminists won’t teach you this. Their understanding is as common as mud, widely accepted as true, but no less supericial on that account. Even Christianity, which is more interested in OT fulfillment through Christ (in whom the whole of the Abrahamic code of law is contained) than the intricacies of the Hebraic code of law and ethics, glide over these kind of messages as often as not.
But for the rabbis, this is their life’s passion. This is their lives work. This is what keeps them up at night.
Sure they are biased.
But they do know their stuff, and there is nothing superficial in the least in the way that they go into the finest detail of that stuff.
That is why.