I think you are forgetting that a film doesn't have a shit load of plot threads they need to wrap up. Person of Interest has been building them for years. When a film comes out, it tells the story it needs to and that's it.

Even if you get all the main stuff out of the way they still have smaller ones to go.

Most things which they saved up thinking they would use them after things were wrapped up in this season. Now they just have to focus on the main central story instead of fleshing out other smaller stories.

"Stories are often better in film or TV if all threads aren't tied up. Take a look at Lost"

LOL

Right first of all this isn't LOST, it's not a mystery show. Second of all a lot of people were ticked off over that ending.

So it's better to have more episodes for a potential final season so they can cover everything. Fringe did alright with 13 episodes but there were still other things fans wanted to see.

LOST held the answers back on purpose, with POI they aren't getting a choice.

Don't see why you are trying to defend crappy Network decisions. This is why decent shows get cancelled while other crap gets made.

EDIT @Below

"Just so you know, JJ Abrams was a huge part in the creating os Lost and Person Of Interest"

And? He doesn't write POI

"Lost tied up all the threads with magic and fantasy BS which killed it and made everyone mad"

URM.....no

They were mad because hardly NOTHING was tied up. There was a shit load of unanswered questions people wanted the answers to. You actually thought people were mad because there was answers ¬¬

"But it was cancelled due to the amount of viewers who watched it"

Potentially cancelled...not cancelled yet

"They didn't just cancel is out of the blue for no reason. This is CBS, not NBC"

It was doing alright. Not amazing but not crap either.