question mark or period?

I don't know if this type of question had been brought up before; if it had I apologize for redundancy.
Please examine the following passages:

"Darcy points out that Mr Bennet has acted with impropriety, but does the reader have to agree with this statement. "
"Her family don't always behave well, especially at the Netherfield Ball,but does he have to keep reminding her about it. "

Why, at the end of both sentences, do the writer use periods instead of question marks ? And I've seen many others do the same thing.

Well, rhetorical questions -questions posed for rhetorical effect rather than for the purpose of gaining an answer - often don't end in a question mark. For example,

[1] Darcy points out that Mr Bennet has acted with impropriety, but does the reader have to agree with this statement.
=> Without the question mark, "but . . . ." means, Darcy can be pompous, so the reader doesn't always agree with Darcy's point of view.

[2] Her family doesn't always behave well, especially at the Netherfield Ball, but does he have to keep reminding her about it.
=> Without the question mark, "but . . . . " means, it's rude and utterly mean of him to continually remind her about her family's behavior.