Perhaps you are speaking of your experience, rather than Author Austen's novels, but she has written characters who are generally agreeable without having any ulterior motives -- or, do you accuse Jane Bennet of duplicity? ;)

When Mr. Knightley, Mr. Bingley, Sir William Lucas, Colonel Brandon, et al, are universally admired or liked, they have a better reason than having delivered elegant flattery that really reflects on how charming they themselves are. Some of them exude warmth and love of fellow human, most of them are active in attempting to care for those who they perceive in need, or have a long history of valuing relationships that do not benefit themselves.

I can think of a better demarcation between the admirable Capt. Wentworth, and the closed-off Mr. Elliot: does the man's attitude show that he cares for those around him, whether it benefits him directly or not? Do his choices reflect his religious principles, or are they the best path chosen to lead him to self-aggrandizement?

Mr. Elliot is verbally delighted with Anne's visits to a stricken school-fellow, but the acquaintances we know of for himself are Colonel Wallis, whomever he was having dinner with at Lansdown Crescent (a more expensive residence than the Elliots' Camden Place house, if my annotated Persuasion is to be believed), and someone who presumably owns an estate called Thornberry Park near Bath. He has no reduced acquaintances, no friends are mentioned who are not top-drawer, he does not even keep up with his in-laws to all appearances, whom we know to be of inferior birth. His convictions lack actions to back them, if we are to believe his protestations.