Ake double fires Netherlands past Gibraltar
Nathan Ake scored twice while Memphis Depay was also on target at De Kuip as Koeman claimed the first win of his second spell in charge, which began with a humbling 4-0 defeat against France three days earlier.
The Oranje's three goals came despite recording 50 shots and having 101 touches in the opposition box - more than they have managed in any other match since Opta began collecting this data in August 2013.
They also registered a remarkable 5.04 expected goals (xG), and Koeman was disappointed by his side's general lacking of a clinical edge.
"I didn't see enough goals tonight," he said. "The opponent obviously didn't co-operate, but we were way too sloppy at times.
"From the beginning, we were inaccurate, and we didn't have the form to create big, good chances. Okay, there was a lot of blocking, but with more sharpness, we score much more often.
"The game and result against France was not good. Now we win, but that makes sense. But overall, it was far too little.
"Aspects such as positional play, ball circulation, taking the right positions - as a winger or defender - really needs to be improved. The football and level has to go up."
Ake's double was the undoubted highlight for the hosts, the defender recording more shot involvements than any other player (nine shots, seven chances created), with only Depay registering more in a single Netherlands match since Opta began collecting the data.
And the Manchester City man drew positives from the fact he and his team-mates were able to conjure as many opportunities as they did.
"Of course, the main aim was to win the match and, besides that, we wanted to score as many goals as possible. Obviously, that didn't work out," Ake added.
"That we created so many chances was good, but maybe we should have been calmer in how we tried to convert them.
"It doesn't happen very often that I score twice in one game. But it was very crowded where our forwards were, so maybe that created a little more space for the rest of us. At some point, I was even considering the possibility of a hat-trick, but it wasn't to be."