Poor ol' Mr. Bennet
The portrait of Mr. Bennet is comparable to a man in a bubble: He is completely shut off from the convoluted life in his household caused primarily by his exceedingly annoying wife, Mrs. Bennet, and his completely different 5 daughters.
Having 5 daughters already puts him on a losing end. No heir meant that his entire estate and hard-earned possessions would go directly to a far cousin, Mr. Collins, after his death. This apparently does not seem to phase Mr. Bennet, who leaves the topic alone, seems "happy go lucky" about it, and retires consistently to read in his library.
Having a wife like Mrs. Bennet is perhaps even more punishing: A woman who consistently demands his attention towards marrying off the daughters, the entailment of Mr. Collins, the behavior of Lizzie and Lynda, and the constant asking of calling on gentlemen to make acquaintance.
Mr Bennet is aloof. He seemingly only reacts to extreme situations such as Lydia's elopement (and Mr Gardiner did more than he did in finding her). He is the typical man who probably had the same arrangements to marry Mrs. Bennet in his youth, for which he had no option, and he takes refuge in his reading.
Had he had sons, instead of daughters, maybe things could have been different: With sons, he would have had to prepare them to become his heirs, they may have had more in common such as hobbies and interests, and certainly it would have taken power away from Mrs. Bennet, since she would have not had anything to nag about. At times it seems that this is actually the source of Mr. Bennet's aloofness and lack of care for his family: He is in the total minority and there is nothing he can do about it.
In Austen's Pride and Prejudice, Mr. Bennet is portrayed as a husband and father who is extremely disturbed because of his family and detached from them.
Mr. Bennet is supposed to be a pitiful character who remains disturbed for his disgusting wife and three difficult-to-handle daughters. His two elder daughters are tolerable to him, amongst them Elizabeth is his most favourite. His wife is a panic for him whose sole concern is to find out good husbands for her daughters, and his daughters are peculiar. Apart from Elizabeth, there is none in his family who is enough sensible and can understand him. So, he keeps himself detached from others by being confined within the study all the day. The reader feels a sort of sympathy toward him.
Yet, Mr. Bennet is himself a careless and irresponsible father to some extents. He is callous to what is happening in his daughtres' lives, since he is almost detached from them. It is partly because of his indifference as a guardian which causes the elopement of Lydia with Wickham. Even, He does not take the responsibility to find out the pair, but the Gardinars and Darcy trace them. The duties that a father should observe in a patriarchal family, Mr. Bennet obviously neglects them. In addition to this, as a husband he is also a failure, since, if he would have looked after his daughters and have had better concern about their future, and not neglected his parental responsibilities, his wife would not have been such hysterical about the marital aspect of the Bennet girls. As the mother of five unwed girl, the wife of a gentleman whose property is going to be entailed by another male relation, where the husband is quite callous to the family affairs, it is not too unnatural for Mrs. Bennet to become over-concerned for her daughters. Probably, a balance could have been brought if Mr. Bennet would be a little more careful and sensible.
Being exhausted by the family members does not necessarily requires a parent to keep himself detached and confined in his own world for which his family might suffer later. Rather, one should take steps to escort and provide security to his family members. So, Mr. Bennet is an escapist after all.