US series are too long.
It is a psychological thing I guess - sitting down and perusing netflix, see something you like but then realise it is 24 hour-long episodes just in the first season. It is a turn off - I can't commit upfront to that amount of time to something entirely unknown to me.
Especially since in a lot of series I've watched, they often lose their way and 99 times out 100 the last 2 or 3 seasons inevitably decay into a "will-they-wont-they" thing about two characters falling in love or whatever, and the rest of the cast and whatever made the series good originally is mostly ignored. Then they're cancelled. So e.g. Lost, US Office, that 70s show and many more all went on way too long while dancing around with romance between two characters etc etc while ignoring what made the first season or two appealing.
Don't get me wrong, I love binge watching something good and I am disappointed when I run out of episodes or whatever, but it is good for people to know when to end a show and leave people with good memories, rather than turning it into a death march where people are relieved to just have finished the show.
Give me 8 to 10 good episodes per season, and please don't string it out for 7, 8, 9 seasons when there is only enough ideas for 2 or maybe rarely 3 seasons's worth of episodes.