The Hebrew Scriptures has a lot to recommend it in terms of human interactions. You can find justifications for almost any despicable act or programme, including for genocide. If you have to turn to those Scriptures for guidelines onbehaviour in the 21st Century, the more you are signalling you are a cult.
The more they sharpen the rhetoric around shunning, the more they are tacitly acknowledging that there are reports of many active Witnesses who routinely ignore the instructions - but don't make a big deal out of it.