OK here is what I think.

We open raise pps from all positions for a few reasons.

In no order:

1.Preflop fold equity - winning the blinds is a perfectly good outcome
2.To build a pot for times when you do hit a set. It's very difficult to play for stacks in a limped pot
3.To balance our opening range
4.They play pretty easily in and oop. Almost always fold to 3 bets preflop.
Post flop get lots of money in w sets. W /out sets pick some good boards to cbet heads up and c/f the rest.