He was easily a top player in the 90s. People who don't think so must not have been around then.
David was elite at both ends of the court, and he also made his teammates better. The problem is that he didn't have a very good collection of teammates most years. Unlike Jordan, Olajuwon, Malone, etc., he never played with another superstar during his prime. Rodman was a great rebounder, but was a liability on both ends of the floor and is the main reason we lost to Houston in the 1995 WCF. Sean Elliott was a two time All-Star, and had some good seasons, but was not the second superstar needed to complement the primary superstar (like Jordan had with Pippen, Olajuwon had with Drexler, Duncan had with Parker, etc.).
It's really amazing that the Spurs were a contender during the first 8 years of David's career, considering the supporting cast David had. It's a testament to his talent and leadership abilities that we were winning 50-60 games all those years.