I've found bgg's weight to be pretty uncorrelated with whether the game actually survives when players make a sincere effort to win. An illustrative sample of games sorted by weight might be Splendor, Wingspan, Res Arcana, Roll for the Galaxy, Race for the Galaxy, Warhammer 40,000: Conquest, A Feast for Odin, and Through the Ages. Of these, the middle games Res Arcana and Roll for the Galaxy completely collapse under the slightest effort to take them seriously, and Wingspan does less than great (you can just tear your ravens in half though, if you want to make things a bit better). Race, Splendor, and Conquest hold up quite well. I don't know enough about the final 2 games to tell whether they'll still be recognizable after 1,000 plays, but it seems like even if a huge part of the options in those games turn out to be unplayably bad the remainder of the options might still contain some interesting choices.