Why wouldn't anyone want bigger legs than that is what I'd question. They look too lanky in my opinion.
Paul DeMayo had legs.
He did, and Paul had other awesome bodyparts. His arms were frickin' amazing.
But to answer your question, in two words: heterosexual women. The vast majority of them would be utterly
repulsed by gigantic wheels like Tom Platz, Demayo and ilk had. Chicks like a lean waistline, good arms, pecs and delts -- and generally only on a middle to lightheavy level at that. Dudes strutting around with stupid-big
anything might turn heads but don't get chicks in their beds. Not the kind of "chicks" most men would like, anyway

Incidentally, and at the risk of sounding "all homo," do you have pics of your own legs that show up Arnold's best? Even so, pretty much everybody admits stupid-big quads are the norm these days .... along with big bellies, shittier conditioning and overall WANK dimensions. The only exception in the pro ranks is Big "Mo," and even he has calves that better befit a ten-year-old girl.
Arnold still owns minds because current bodybuilders know they'll NEVER inspire people to take up training the way Arnold did. Heath is a jealous little bitch and legend in his own mind. I bet he has nightmares about competing against Jay, Coleman and Martinez at 90% of their respective bests.