That is
EXACTLY the point! Where people get confused is the difference between good and excellent redemptions versus poor and good redemptions. I would categorize an upgrade from J to F on a long haul route like LHR to be good given the points involved. Consider the fact that the OP could have spent more points on a set of OXO kitchen organizers:
View attachment 317770
Now you're telling me with a straight face that a 20 piece set of plastic kitchen organizers is better value than a first class seat on a 20+ hour flight? You gotta be kidding me!
Indeed when
AFF crunched the numbers on the value of a Qantas point when redeemed for various items, it was precisely the upgrade from business to first that provided the most value in terms of a cent per point valuation:
-RooFlyer88