Yup, once they committed to the Dany/Jon fatal attraction while the will we come back another season or two or not stuff was going on they basically boxed themselves in, and they could have seamed things better with the characters as you say but I am not sure how/when the decisions were made, but it seems to me the see/saw nature indicates a can kicking and the writers had to do what they had to do episode to episode without time to properly flesh things out and so the uncertainty and the lack of time commitment forced the rush. It is odd that a production that for most of its existence took the time to develop characters as well as develop their demise was forced to rush and mash things through at the end. Seriously, if allowed to extend even just a couple more episodes in order to better tie things off would have been preferable but it is what it is. The quality has been so good people got spoiled and it affects expectations, that being said I have no brook with the outcome like you say as well, it makes sense...and I like that some mystery remains.
It is one heck of a series, clearly one of the better things broadcast in a while.
Pretty sure nothing replacing it in my viewing habits...