I tend to the view that Bingley's greatest faults are a well-deserved confidence in his friend's judgement and discernment. One author has pointed out - correctly IMO - that Bingley reposes very little confidence in his sister's opinions. I won't repeat somne of the points made previously but in four instances his confidence in his own opinion is clear:
1. He leased Netherfield despite his sisters'm objections to the area;
2. They attended the Assembly despite their objections;
3. He hosted the ball despite Caroline's objections; and,
4. He would have returned to Netherfield despite their objections - as stated by Darcy.
It is only with respect to the decision as to whether Jane held him in affection that he fell short. Reposing his confidence in Darcy does not seem unwarrented and darcy's advice is not wrong insofar as he could discern Jane's feelings; his error does not invalidate his decision or his advice given the other impediments he saw. I do not think him wrong to believe that Jane would have been persuaded by her mother to accept such an offer. There is nothing in Jane's behaviour to suggest the strength of will to stand against her mother and truthfully, I suspect, most people of that era would have been surprised if Jane did not accept an offer even if she were not in love with Bingley. She had reached the age of twenty three without a sensible offer being made to her and the paucity of suitors - although not mentioned - would, I am sure, weighed heavily on her and her mother.