I can argue with that. He played in one team - that makes him, understandably, biased. Both sides were great, but the evidence - winning trophies and competing for them - demonstrably proves that the 1980s team was clearly superior. Two league titles, one FA Cup, and a Cup Winners' Cup - we'll ignore the three and a half Charity Shields, a League Cup final, two FA Cup finals, and a league runners-up spot - utterly trump one league title (and, at a stretch, an FA Cup final defeat two years earlier).
Style and preference is a matter of taste, but achievement is more objective. Our greatest side was in the 1980s and it's not even close.