He’s always done the job that he was hired to do very well and that is managing the bottom line, cap/tax implications and answering to his bosses. The GM job isn’t always about Championships or even Wins and Losses. He was also magnificent for many years in Memphis under circumstances so challenging that most wouldn’t have made it out of their second year.
I'm not questioning your "well, he did what they asked him to do in Memphis" POV. It would be like beating up Harry Sinden for trading good players for 20 years for kids because Jeremy Jacobs sucked. That's the job.
Wallace had full control over the 2001 draft though and fucked the pooch. It's not the only thing that he did wrong here, but it's the worst.
fake edit: that saying is wrong on purpose
real edit: Just looked at the wiki for Wallace and saw that his first NBA job was as a hire for Jon Spoelstra, father of Erik and son of a legendary Detroit sportswriter. Had no idea that Spoel was third generation sports royalty.