I think he's a center because he fits a team better in a Sam Perkins type role than trying to be some all purpose PF. On offense, he is a PF when Tristan is in the game. On defense, he is a center. This is like the whole Tim Duncan argument. Both offensively and defensively, he played like a center. He almost always guarded the other team's slowest and biggest guy.
If you put Love next to a guy like Draymond Green, Porzingis, Iggy, Millsap, Harrison Barnes, and others, he would be an incredible center. He's better as a center in today's NBA, especially the playoffs, than he is at PF. Look at him next to a noshoot "center" in TT, and you'll see his numbers were nonexistent when the Cavs won the finals 2 years ago. He struggled again last year.
As for the #1 option, yes, he was in Minnesota. And the team sucked really badly while he put up great stats. He is better as a 3rd option if you want your team to win. Kyrie (when he was with the Cavs) and now that he's gone has proven that. Love doesn't lead to wins.