Since he took total control they haven't finished lower in the Premiership than 4th and were runners up last year playing the best football in the division. They have made the European Champions league every year.
They have also won the FA Cup twice after having gone ten years without it under the previous owners.
The problem Arsenal fans have is for about a decade from the mid 90's their only competition was Man Utd. They pretty much swapped the title every year.
Then Chelsea burst on the scene with Roman Abramovich spending some of his billions and it became more competitive.
Then Man City got bought out by a Middle Eastern conglomerate and suddenly they were rolling in cash and Champions.
Meanwhile Liverpool have steadily improved so now it's a real fight. Worse still their bitter North London rivals, Tottenham have improved.
Arsenal haven't won the Premiership in well over a decade, long before Kroenke took control, but he's given Wenger more money to spend (by a long way), than the previous ownership did.
Even when Arsenal were winning so many titles Wenger was known for being reluctant to pay exorbitant fees. He's relaxed on that somewhat and joined the fray with Kroenke financing some huge signings.
He's very unpopular with frustrated Arsenal fans, but that's sooooo common with any team who aren't achieving what the fans want, or more accurately expect.
The owner of my team, Derby, is a life long supporter and poured a lot of many into the club but he's still unpopular because we've been stuck in the 2nd tier for almost 10 years even though every year we're competing for promotion to the Premiership.
I'm no fan of Kroenke, far from it, but his record at Arsenal is pretty good.
There is nothing either good or bad, but thinking makes it so.