This match pretty much sums up why Liverpool won't be able to win anything with the squad they have. People saying that Klopp should've changed his tactics after 2-0, Arsenal scored their first two goals within 3 minutes of Liverpool grabbing the second. How drastically can you expect tactics to change within that time that you can blame Klopp for that; especially the second goal, it was a wild pop from Xhaka that even a schoolboy keeper should've saved.
Then you look at the first half and see the not just the amount of but also the quality of chances his strikers missed to effectively end the game then and there (though you can never really say that with Liverpool).
There have been plenty of games where blame can be given to Klopp for failing to control the opposition after taking the lead, but this surely isn't one of them. He played his tactics perfectly, contributed by Arsene playing his poorly in the first half, but his players let him down massively.