I said "isn't really an "offensive" position." Because it isn't, and hasn't been. You took it from there.
It does have to do with defensive ability. The ability to play the position. Most MLB players don't have the ability to play 3B at an acceptable level. Beltre does, that's a valuable thing. A decent amount of players can hit like Beltre does, but they can't play 3B.
It looks like not much has changed since the 70s, aside from middle infielders becoming better hitters. If there was a term people used called "defensive position" in referring to the middle infield, ok. I wasn't trying to use a specific 70s-age baseball term when I said "wasn't really an "offensive" position."
Again, a lot of people seem to look at 3B as having a similar offensive skillset to 1B and COF. That's never been true.