Earnest, Earnest, Earnest...
Where do I start?
You first have to realize that there is NO SUCH THING as a "JW understanding of the Scriptures in this regard"... In fact, most JWs just blindly follow whatever illogical Bible text "interpretations" come from Brooklyn... plain and simple.
And when it comes to "abstaining from blood", these Brooklyn whack jobs have clearly over-interpreted certain Bible texts and now find themselves back-peddling because of they've "gone beyond what is written" to the point of causing unnecessary deaths (not to mention financially burdensome litigation).
That being said, I think MOST people (JW or not) prefer NOT to have transfusions... except most people wouldn't risk the lives of their loved ones over some arbitrary Bible interpretation by people that haven't even met in person...