Why is it difficult for Emily to meet suitable men in her youth in "A Rose for Emily"?

Emily’s father drove all of her suitors away. 

The entire town knows Emily.  Emily is eccentric, and her father was even more eccentric.  He is the reason that she ended up alone.  Her father actually drove away the young men who came courting with a horsewhip.

None of the young men were quite good enough for Miss Emily and such. We had long thought of them as a tableau, Miss Emily a slender figure...

Emily’s father drove all of her suitors away. 

The entire town knows Emily.  Emily is eccentric, and her father was even more eccentric.  He is the reason that she ended up alone.  Her father actually drove away the young men who came courting with a horsewhip.

None of the young men were quite good enough for Miss Emily and such. We had long thought of them as a tableau, Miss Emily a slender figure in white in the background, her father a spraddled silhouette in the foreground, his back to her and clutching a horsewhip, the two of them framed by the back-flung front door. (II) 

Emily’s erratic behavior is the stuff of legend.  When her father died, she refused to let them have the body to bury it, saying that her father was not dead.  She finally broke down and let them in after three days.

We did not say she was crazy then. We believed she had to do that. We remembered all the young men her father had driven away, and we knew that with nothing left, she would have to cling to that which had robbed her, as people will. (II)

Emily might have inherited some mental instability from her family.  The townspeople are really not that surprised that she hasn’t left the house since Homer Barron disappeared.  Homer himself said he was not a marrying man, and the town felt sorry for her when he left (or so they said). 

Emily obviously wanted to make sure that if she could not have Homer, no one could.  She told the pharmacist that she wanted arsenic for rats.  When a strange smell came out of her house, she drove away the people who came about it.  She always behaved so oddly that no one really questioned it.  They just believed that her male housekeeper couldn’t keep a kitchen well.  They were afraid to confront her, and instead broke in and sprinkled lime, and after time the smell went away.  It wasn’t until Emily herself died that they found Homer’s body.