ill atleast try to play devils advocate's advocate.
since Man to man defense was more prevalent when Rodman was playing. Maybe being an elite defensive player back then was looked at with more prestige than it is today? Fans would see you jump on your assignment and sit back and watch you shut him down. The direct impact was more obvious to the untrained eye with that setup.
Defense goes very underappreciated in todays era...defense is more complex and you impact your team in ways that arent as obvious perhaps. zones, switches, perimiter contests on D, screens on O which are crucial in todays game... no one bigs up players who do all those things well because it doesnt really jump out at the screen at you, as opposed to back when people were just seeing you locking someone down toe to toe or out hustling ppl for rebounds all game...