Because at United we have bigger expectations. Our fans even during sir alex era were demanding to an extent even after winning the CL in 08 , we became critical of him for dropping Tevez or after winning league in 10/11, we were critical of him for playing Scholes and Giggs or on many other occasions. That's what United fans are and other big teams like.madrid and barca are also the same(ok maybe not to an extent of Madrid fans who are crazy).
If you think United fans would have been blindly jizzing over klopp like you lot after 3 years then you have no clue. Fans would have been divided for him too if he was not winning and just screwing over at the crunch time. Klopp is performing in a safe atmosphere where you lot are just glad to be in top 4 and score some amazing goals. You lot are reminding me alot of arsenal fans from 2006 to 2013. If klopp doesnt win anything then all this hype will look foolish just like it looked with Wenger post 06. All the pretty football with no substance.