The players of today aren't bigger, stronger, and faster, due to an evolutionary change in the human stature since 1985. They're bigger stronger and faster because of weight training, nutrition, and occasionally chemistry.
You put those players on the old Lakers, Celtics, and 76ers, on the same kind of training regimen and they would be equally bigger,faster, and stronger. So you have to compare how these teams were against the competition of their era, and the degree of quality competition in their era.
In the end it becomes a subjective argument regardless of how you slice it.